CA1270113A - Method for determining formation dip - Google Patents
Method for determining formation dipInfo
- Publication number
- CA1270113A CA1270113A CA000519304A CA519304A CA1270113A CA 1270113 A CA1270113 A CA 1270113A CA 000519304 A CA000519304 A CA 000519304A CA 519304 A CA519304 A CA 519304A CA 1270113 A CA1270113 A CA 1270113A
- Authority
- CA
- Canada
- Prior art keywords
- formation
- bit
- interface
- sensor
- downhole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 64
- 238000000034 method Methods 0.000 title claims description 23
- 238000005452 bending Methods 0.000 claims abstract description 26
- 238000005259 measurement Methods 0.000 claims abstract description 13
- 230000003993 interaction Effects 0.000 claims abstract description 6
- 230000005484 gravity Effects 0.000 claims abstract 3
- 238000005553 drilling Methods 0.000 claims description 34
- 238000011156 evaluation Methods 0.000 claims description 13
- 230000005251 gamma ray Effects 0.000 claims description 3
- 230000005055 memory storage Effects 0.000 claims description 2
- 238000001914 filtration Methods 0.000 claims 1
- 238000005755 formation reaction Methods 0.000 abstract description 34
- 238000012545 processing Methods 0.000 abstract description 2
- 239000011435 rock Substances 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/02—Determining slope or direction
- E21B47/026—Determining slope or direction of penetrated ground layers
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B44/00—Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/007—Measuring stresses in a pipe string or casing
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/02—Determining slope or direction
- E21B47/022—Determining slope or direction of the borehole, e.g. using geomagnetism
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
- E21B49/003—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells by analysing drilling variables or conditions
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
Landscapes
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
Abstract of the Disclosure The inclination and slope of a bedding plane are deter-mined from oriented measurements of the bending moment gener-ated as a bit encounters and passes completely through the interface between two dissimilar formations. These moments are distinguishable from moments generated by gravity, interaction of the bit and the formation, and interaction of the drill string with the borehole. Preferably, determination of the bedding slope and direction is accomplished by downhole data processing.
Description
~2~0~3 .
Background of the Invention 1. ~ield of the Invention The pre3ent invention relates to a method employing mea-surement of magnitude and direction of the bend~ng moments near a drill bit to estimate formation dip at ~n interface.
Background of the Invention 1. ~ield of the Invention The pre3ent invention relates to a method employing mea-surement of magnitude and direction of the bend~ng moments near a drill bit to estimate formation dip at ~n interface.
2. Description of the Prior Art The dip of a formation is useful to geologis~s and re-~ervoir engineers in defining the type, 8ize and the profile of a reservoir. Further, this information i8 useful for ex-plaining directional drilling tendencies, for correlating li-thology, and for detecting faults in a format~on. The ~ngle (magnitude) and direction of the formatio~ dip iB presently ~easured by pas~ing a hard wired, wireline device ~hrough a completed hole. Although mea~urements made by this ma~ner provide useful information, they are of no help to the drilling engineer during the drilling operation.
BecauRe the dip of ~ formation ~an affect the ~ide force~
acting on a bit while drilling, knowledge of the formatlon dip would be most useful to the drilling engineer particularly, when he i8 attempting directional drilling. The present invention provide~ a method which is useful for predi~ting or determining the magnitude langle) and direction of formation dip by measuring the magnituae and directlon of bending moments on the bit while the drilling operation co~tinues. Mea~ure-ments of the bending moment are made in tw~ orthogonal planesproviding both magnitude and direction for the bending moments.
This is accomplishe~ by monitoring the direction of the two - orthogonal plane~ by u~ing oriented magnetometer mea~urements.
U.S. Patent No. 4~445,578 to Millheim disclo~es ~n appa-ratus and methcd for providing mea~urement of the side force ona drill bit durin~ drilling, thus permitting corrective act~on to be taken immediately in the drilling operation. The ~illheim system $nclude!s means to dete~t the side thrust or force on a bit and the force on the deflection means of a downhole motor.
Thi3 system provides for measuring the magnitude of the force on a downhole stabilizer. While Millhelm discloses mean~ for measuring various force3 acting near the drill b~t and cor ..... . .
:
~: :
disclose or suggest any way in which these measurements can be used to make a determination of the formation aip. The ~ide force6 at the bit or at a sub ~re measured by using multiple stra~n g~uges or load cells and transmitting the measurement~
ba~k to the surface. The sampling rate i8 limited by the transmi~sion rate. The measured forces are then used to determine the directlonal tendencies of the hole. The orienta-tion of the side forces are not measured, but periodic surveys of the hole are made to determis~e lts direction during rotary drilling.
~ .S. Patent No. 4,324,297 to Deni~on discloses a method and apparatus f or measuring the weight on bit, the bending stress near the bit, and the orient~tion of these stresses.
These measurements ~re sent to the surface by wire line tele-metry or other high data rate transmission means including mudpulse telemetry. The data i8 pro~essed at the sur~ace to compare the measured 8i~e forces with a drilling model for controlling the directional tendencies by adjusting weight on bit. This patent teaches the u~e of oriented bending moments for directional control. ln order to effectively impleme~t the teachin~s of t~is patent it is necessary to have a high ~ata rate telemetry system. However, this patent does not mentioD
anything about measuring the formation dip or how interaction with a formation face will affect the steering or the possi-bility o~ utilizing downhole processing to avoid transmissionrate limitations and asscciated problems.
..
, . ',.-. ' ' , : , .
, lZ7G113 .
Summary of the Invention The present invention utilizes bending moment measure-ments taken by a bit mechanics sellsor coupled with ~n oriented m~gnetometer mensurement of borehole heading to determine ~he m~gn~tude (~ngle) and direction of the dip of ~ formation encountered during ~ drilling operation. Wmen the blt encounters a change from one forn~ltion to another, the drilling rate should change. If the formation dip is normal to the axial directlon of the bit~ then the direction and magnltude of the bend~ng moment ~hould not change. ~owever, ~f the bit encoun-ters a new formation at an angle other than ninety degrees to the bit axis, one ~ide of the bit ~hould see the new formation sooner than the other side~ Accordinqly, a detectable bending ment should be generated at this point with the size and direction of the bending moment indicating the magnitude and direction of ~ormation dip.
,~.~ . . .
.. . .
, ~' . .:', -, :
12701:l3 . ..
Brief Description of the Drawin~
The pre~ent inventlon will be described by way of example with reference to the accompanying drawings in which:
Fig. 1 i8 a diagrammatic vi~ew of ~ straight borehole in homogeneous rock;
Fig. 2 is a diagrammatic view of a directional borehole in homogeneous rock;
Fig. 3 $s a diagrammatic view of a straight borehole encountering a formation change; and - 10 Fig. 4 is a diagrammatic view of a directional borehole encountering a formation change.
`:~
. " .~, . . .
.-, ~ i ~ .
.: ... , , . :.
,- - .
~7C113 DescriPt~on of Preferred Embodiments Until now, formation dip (magnitude and direction) has only ~een measured by using a wirellne device ~ftQr the borehole has been drilled. ~owever, the inPormation on form~t~on dlp i8 S extremely important to geologists and reservoir çngineers in order to define reservoir type, ~size and shape. Therefore, ~t is important that this information be made avail~ble as 800n a~
possible and preferably without interrupting the drilling operation.
Referring now to Figs. 1 and 2, ~ bottom hole a~sembly 10 including a drill bit 12 is shown in the bo~tom of a borehole 14 drilled in a hom~geneous rock formation 16. In this situation, ~s one would expect, the average bending ~oment would have no preferential direction; in other words, there would be no net tendency of the bit to drill laterally. The bit force would be substantially axial and vertical a~ noted by the arrow 18.
In the directional hole of Fig. 2, the borehole 14 is at an angle other than vertical. In this instance the biS would have a side force who~e magnitude and airection would be dependent upon the forces measured on the bit due to gravi-tational effects and axial forces in the drill string due to tension applied at the surface (hook load). ~hus, the total bit force, represented by arrow 24, woul~ have a gravaty component 20 depend~nt upon the bit moment 22 and an axial co~ponent 18.
As in the case of Fig. 1, the directional hole of Fiy. 2 i~
assumed to be drilling through homogeneous rock.
Figs. 3 and 4 demonstrate ~he concept of the present invention which notes that there will be a near bit bending moment generated when the bit traverses a bedding plane between formations. It will be appreciated that the forces encountered by opposite sides of the bit will be different because each will be engaginy rock having differe~t drilling characteri~tics. In both instances~ one s$de of the ~it, noted ~y the arrow Fa, will be drilling in the origin~l ormation while the opposite side of the bit, noted by the arrow Fb~ will be drilling ln a different or second formation. ~his w$11 c~use ~lt moment~ 26, . ,~, . .
, ~ ~, ,, : -, ':
:~ .. , : , "
.:. ,,, ~"' .-. ., ' : , : ' ";'' ~, ... ~ .
;;.
: . . . ,: -formation to another, the dr~lling rate changes~ If, however, the bedding plane i~ normal to the actual direction of the bit, one would not exp~ct Any directional effect~ on the bit, and hence the direction of existing bending moment~ will not change. ~owever, if the bit encounters ~ new formation ~t an angle other than ninety degree~ to the bit axis, one side of the bit will see the new formation sooner than the other ~ide.
Since the bit i8 drilling in rock having two different drilling characteristic~, one would expect a bending moment to be 1~ generated at this point. The size and direction of the bending moment would be indicative of the m2gnitude of the formation dip and its directionO In thi~ way, the bending moments measured by a bit mechanics ~ensor coupled with oriented ~agnetometer reading~ can be used to develop estimates for formation dip and its direction.
~ he invention recogni~es that drilling a well i9 not a smooth boring operation. There i~ an almost continual series of bit bending moments being generated a8 the bit advances through the formation. These moments can be caused by $nter-action between the bit and the format~on. Other moments can begenerated by gravitational effects on the drill string, the mechanics of the drill string itself which acts, in many way~, as a giant compre~sion ~pringt and the interaction of the drill string with the borehole. ~owever, these moment~ are of ~uch nature as to be readily identifiable and distinguishable. The signals generated by these moments can be treated ag ~noi3e~ or ~chatter" and appropriately filtered~ The present invention - focuse~ on the significant sustained moment generated as the bit passex through a formation interface.
In order to determine the formstion dip, it is necessary to know ~he dixection of drilling, including both azimuth and inclination. The bit bending moment and its direction are sampled frequently, approximately once every inch of hole drilled. The rate of ~ampling required depends upon the drilling rate. When the drilling rate changes, ~ndicating a change in formation character, the bending moment d~ta taken during the change in drilling rate i~ analyzed to determine the ~. .... .
~270~3 ling. As an alternativetothe drilling rate as an ~ndicator o~
forma~ion change, a measurement-while-drill~ng fonmation log-ging de~ice (e.g. gamma ray sensor) can be used. The foxmation logging device i8 usually located some distance above the b~t.
This alternative method, of necessity, delay~ the determina-tion of formation dip until the formation change has been identified by the formation logging device. It ~s pos~ible to accomplish all of the~e measurements with state-of-the art downhole equipment.
It i8 proposed in the present invention that the downhole equipment include a microprocessor and memory 80 that ~he occurrence and ending of the bending moment~, together with bit orientation and inclination and the presence of the formation interfac~, can he readily and rapidly determined without send-ing all the needed data to the surface~ This allows a downhole sampling rate independent of the downhole-to-~urface trans-mission rate. While no ~ampling rate i8 specified, it would have to ~e high enough to get measurements for every inch or 80 of borehole. The rate of sampling would be dependent upon drilling rate. The data on the ~ormation interface could be both stored downhole, for subsequent readout at the surface when the drill string is withdrawn for bit replacement~ or transmitted to the surface. ~his would not requlre a high transmission rate as the data would have been processea and only the resulting determi~ation transmittea.
~. ..
. ~ - .
... . .
~: :
~70~3 -8a-The determination from the measurements of the magnitude (angle) and direction of the formation dip may be compared with known geological survey information.
The formation evaluation sensor may be a neutron porosity sensor, or a gamma-gamma density sensor or a formation resistivity sensor.
The presence of the interface may be detected through a normalized drilling rate measured at the surface.
Where a microprocessor is provided located downhole in an equipment sub, the microprocessor may comprise memory storage means.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the method steps may be made within the scope of the appended claims without departing from the spirit of the invention.
~f~
~: : -- , ' `
'' ' ::. .. .
BecauRe the dip of ~ formation ~an affect the ~ide force~
acting on a bit while drilling, knowledge of the formatlon dip would be most useful to the drilling engineer particularly, when he i8 attempting directional drilling. The present invention provide~ a method which is useful for predi~ting or determining the magnitude langle) and direction of formation dip by measuring the magnituae and directlon of bending moments on the bit while the drilling operation co~tinues. Mea~ure-ments of the bending moment are made in tw~ orthogonal planesproviding both magnitude and direction for the bending moments.
This is accomplishe~ by monitoring the direction of the two - orthogonal plane~ by u~ing oriented magnetometer mea~urements.
U.S. Patent No. 4~445,578 to Millheim disclo~es ~n appa-ratus and methcd for providing mea~urement of the side force ona drill bit durin~ drilling, thus permitting corrective act~on to be taken immediately in the drilling operation. The ~illheim system $nclude!s means to dete~t the side thrust or force on a bit and the force on the deflection means of a downhole motor.
Thi3 system provides for measuring the magnitude of the force on a downhole stabilizer. While Millhelm discloses mean~ for measuring various force3 acting near the drill b~t and cor ..... . .
:
~: :
disclose or suggest any way in which these measurements can be used to make a determination of the formation aip. The ~ide force6 at the bit or at a sub ~re measured by using multiple stra~n g~uges or load cells and transmitting the measurement~
ba~k to the surface. The sampling rate i8 limited by the transmi~sion rate. The measured forces are then used to determine the directlonal tendencies of the hole. The orienta-tion of the side forces are not measured, but periodic surveys of the hole are made to determis~e lts direction during rotary drilling.
~ .S. Patent No. 4,324,297 to Deni~on discloses a method and apparatus f or measuring the weight on bit, the bending stress near the bit, and the orient~tion of these stresses.
These measurements ~re sent to the surface by wire line tele-metry or other high data rate transmission means including mudpulse telemetry. The data i8 pro~essed at the sur~ace to compare the measured 8i~e forces with a drilling model for controlling the directional tendencies by adjusting weight on bit. This patent teaches the u~e of oriented bending moments for directional control. ln order to effectively impleme~t the teachin~s of t~is patent it is necessary to have a high ~ata rate telemetry system. However, this patent does not mentioD
anything about measuring the formation dip or how interaction with a formation face will affect the steering or the possi-bility o~ utilizing downhole processing to avoid transmissionrate limitations and asscciated problems.
..
, . ',.-. ' ' , : , .
, lZ7G113 .
Summary of the Invention The present invention utilizes bending moment measure-ments taken by a bit mechanics sellsor coupled with ~n oriented m~gnetometer mensurement of borehole heading to determine ~he m~gn~tude (~ngle) and direction of the dip of ~ formation encountered during ~ drilling operation. Wmen the blt encounters a change from one forn~ltion to another, the drilling rate should change. If the formation dip is normal to the axial directlon of the bit~ then the direction and magnltude of the bend~ng moment ~hould not change. ~owever, ~f the bit encoun-ters a new formation at an angle other than ninety degrees to the bit axis, one ~ide of the bit ~hould see the new formation sooner than the other side~ Accordinqly, a detectable bending ment should be generated at this point with the size and direction of the bending moment indicating the magnitude and direction of ~ormation dip.
,~.~ . . .
.. . .
, ~' . .:', -, :
12701:l3 . ..
Brief Description of the Drawin~
The pre~ent inventlon will be described by way of example with reference to the accompanying drawings in which:
Fig. 1 i8 a diagrammatic vi~ew of ~ straight borehole in homogeneous rock;
Fig. 2 is a diagrammatic view of a directional borehole in homogeneous rock;
Fig. 3 $s a diagrammatic view of a straight borehole encountering a formation change; and - 10 Fig. 4 is a diagrammatic view of a directional borehole encountering a formation change.
`:~
. " .~, . . .
.-, ~ i ~ .
.: ... , , . :.
,- - .
~7C113 DescriPt~on of Preferred Embodiments Until now, formation dip (magnitude and direction) has only ~een measured by using a wirellne device ~ftQr the borehole has been drilled. ~owever, the inPormation on form~t~on dlp i8 S extremely important to geologists and reservoir çngineers in order to define reservoir type, ~size and shape. Therefore, ~t is important that this information be made avail~ble as 800n a~
possible and preferably without interrupting the drilling operation.
Referring now to Figs. 1 and 2, ~ bottom hole a~sembly 10 including a drill bit 12 is shown in the bo~tom of a borehole 14 drilled in a hom~geneous rock formation 16. In this situation, ~s one would expect, the average bending ~oment would have no preferential direction; in other words, there would be no net tendency of the bit to drill laterally. The bit force would be substantially axial and vertical a~ noted by the arrow 18.
In the directional hole of Fig. 2, the borehole 14 is at an angle other than vertical. In this instance the biS would have a side force who~e magnitude and airection would be dependent upon the forces measured on the bit due to gravi-tational effects and axial forces in the drill string due to tension applied at the surface (hook load). ~hus, the total bit force, represented by arrow 24, woul~ have a gravaty component 20 depend~nt upon the bit moment 22 and an axial co~ponent 18.
As in the case of Fig. 1, the directional hole of Fiy. 2 i~
assumed to be drilling through homogeneous rock.
Figs. 3 and 4 demonstrate ~he concept of the present invention which notes that there will be a near bit bending moment generated when the bit traverses a bedding plane between formations. It will be appreciated that the forces encountered by opposite sides of the bit will be different because each will be engaginy rock having differe~t drilling characteri~tics. In both instances~ one s$de of the ~it, noted ~y the arrow Fa, will be drilling in the origin~l ormation while the opposite side of the bit, noted by the arrow Fb~ will be drilling ln a different or second formation. ~his w$11 c~use ~lt moment~ 26, . ,~, . .
, ~ ~, ,, : -, ':
:~ .. , : , "
.:. ,,, ~"' .-. ., ' : , : ' ";'' ~, ... ~ .
;;.
: . . . ,: -formation to another, the dr~lling rate changes~ If, however, the bedding plane i~ normal to the actual direction of the bit, one would not exp~ct Any directional effect~ on the bit, and hence the direction of existing bending moment~ will not change. ~owever, if the bit encounters ~ new formation ~t an angle other than ninety degree~ to the bit axis, one side of the bit will see the new formation sooner than the other ~ide.
Since the bit i8 drilling in rock having two different drilling characteristic~, one would expect a bending moment to be 1~ generated at this point. The size and direction of the bending moment would be indicative of the m2gnitude of the formation dip and its directionO In thi~ way, the bending moments measured by a bit mechanics ~ensor coupled with oriented ~agnetometer reading~ can be used to develop estimates for formation dip and its direction.
~ he invention recogni~es that drilling a well i9 not a smooth boring operation. There i~ an almost continual series of bit bending moments being generated a8 the bit advances through the formation. These moments can be caused by $nter-action between the bit and the format~on. Other moments can begenerated by gravitational effects on the drill string, the mechanics of the drill string itself which acts, in many way~, as a giant compre~sion ~pringt and the interaction of the drill string with the borehole. ~owever, these moment~ are of ~uch nature as to be readily identifiable and distinguishable. The signals generated by these moments can be treated ag ~noi3e~ or ~chatter" and appropriately filtered~ The present invention - focuse~ on the significant sustained moment generated as the bit passex through a formation interface.
In order to determine the formstion dip, it is necessary to know ~he dixection of drilling, including both azimuth and inclination. The bit bending moment and its direction are sampled frequently, approximately once every inch of hole drilled. The rate of ~ampling required depends upon the drilling rate. When the drilling rate changes, ~ndicating a change in formation character, the bending moment d~ta taken during the change in drilling rate i~ analyzed to determine the ~. .... .
~270~3 ling. As an alternativetothe drilling rate as an ~ndicator o~
forma~ion change, a measurement-while-drill~ng fonmation log-ging de~ice (e.g. gamma ray sensor) can be used. The foxmation logging device i8 usually located some distance above the b~t.
This alternative method, of necessity, delay~ the determina-tion of formation dip until the formation change has been identified by the formation logging device. It ~s pos~ible to accomplish all of the~e measurements with state-of-the art downhole equipment.
It i8 proposed in the present invention that the downhole equipment include a microprocessor and memory 80 that ~he occurrence and ending of the bending moment~, together with bit orientation and inclination and the presence of the formation interfac~, can he readily and rapidly determined without send-ing all the needed data to the surface~ This allows a downhole sampling rate independent of the downhole-to-~urface trans-mission rate. While no ~ampling rate i8 specified, it would have to ~e high enough to get measurements for every inch or 80 of borehole. The rate of sampling would be dependent upon drilling rate. The data on the ~ormation interface could be both stored downhole, for subsequent readout at the surface when the drill string is withdrawn for bit replacement~ or transmitted to the surface. ~his would not requlre a high transmission rate as the data would have been processea and only the resulting determi~ation transmittea.
~. ..
. ~ - .
... . .
~: :
~70~3 -8a-The determination from the measurements of the magnitude (angle) and direction of the formation dip may be compared with known geological survey information.
The formation evaluation sensor may be a neutron porosity sensor, or a gamma-gamma density sensor or a formation resistivity sensor.
The presence of the interface may be detected through a normalized drilling rate measured at the surface.
Where a microprocessor is provided located downhole in an equipment sub, the microprocessor may comprise memory storage means.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the method steps may be made within the scope of the appended claims without departing from the spirit of the invention.
~f~
~: : -- , ' `
'' ' ::. .. .
Claims (31)
1. A method for determining the magnitude (angle) and direction of the dip of a formation interface encountered by a bit while drilling and without interrupting the drilling oper-ations, said method comprising the steps of:
measuring near bit bending moments generated when said bit encounters said formation interface until said bit passes com-pletely therethrough;
measuring the direction of said bit bending moments while said near bit moments are being generated;
measuring the inclination and direction of the wellbore at the location of the formation interface; and determining from said measurements the magnitude (angle) and direction of the formation dip.
measuring near bit bending moments generated when said bit encounters said formation interface until said bit passes com-pletely therethrough;
measuring the direction of said bit bending moments while said near bit moments are being generated;
measuring the inclination and direction of the wellbore at the location of the formation interface; and determining from said measurements the magnitude (angle) and direction of the formation dip.
2. A method according to Claim 1 further comprising the step of:
detecting the presence of the interface by use of a downhole accelerometer whose readings are indicative of a change in formation character.
detecting the presence of the interface by use of a downhole accelerometer whose readings are indicative of a change in formation character.
3. A method according to Claim 1 wherein said near bit moments are measured using a bit mechanics sensor.
4. A method according to Claim 1 wherein said direction of said bit bending moments are measured by oriented magneto-meters.
5. A method according to Claim 1 wherein said deter-mination of magnitude and direction of a formation interface is done by a microprocessor located downhole in an equipment sub of a drill string.
6. A method according to Claim 5 wherein said micro-processor stores formation dip information downhole and causes it to be transmitted to the surface.
7. A method according to Claim 1 further comprising the step of:
filtering out near bit moments caused by gravity, drill string mechanics, and interaction of the drill string with the borehole.
filtering out near bit moments caused by gravity, drill string mechanics, and interaction of the drill string with the borehole.
8. A method according to Claim 1 further comprising the step of:
measuring the depth of said bit and inclination and direction of the wellbore where said interface is detected.
measuring the depth of said bit and inclination and direction of the wellbore where said interface is detected.
9. A method according to Claim 1 further comprising the step of:
comparing said determination with known geological survey information.
comparing said determination with known geological survey information.
10. A method according to Claim 1 further comprising the step of:
determining the presence of the interface by use of a downhole measurement-while-drilling formation evaluation sen-sor.
determining the presence of the interface by use of a downhole measurement-while-drilling formation evaluation sen-sor.
11. A method according to Claim 10 wherein said formation evaluation sensor is a gamma ray sensor.
12. A method according to Claim 10 wherein said formation evaluation sensor is a neutron porosity sensor.
13. A method according to Claim 10 wherein said formation evaluation sensor is a gamma-gamma density sensor.
14. A method according to Claim 10 wherein said formation evaluation sensor is a formation resistivity sensor.
15. A method according to Claim 10 wherein said formation evaluation sensor includes a combination of sensor devices.
16. A method according to Claim 1 further comprising the step of:
determining the presence of the interface wherein said interface is detected through a normalized drilling rate mea-sured at the surface.
determining the presence of the interface wherein said interface is detected through a normalized drilling rate mea-sured at the surface.
17. A system for determining the dip of a formation interface encountered in a drilling operation comprising:
means to measure a near bit bending moment generated by a bit encountering and passing through said interface;
means to measure the orientation of said bit bending moment while said moment is present;
means to measure the inclination and orientation of the wellbore at the location of the interface; and means to determine the dip of a formation interface from said near bit bending moment measurements and said orientation and inclination measurements.
means to measure a near bit bending moment generated by a bit encountering and passing through said interface;
means to measure the orientation of said bit bending moment while said moment is present;
means to measure the inclination and orientation of the wellbore at the location of the interface; and means to determine the dip of a formation interface from said near bit bending moment measurements and said orientation and inclination measurements.
18. A system according to Claim 17 further comprising:
means to filter out near bit moments caused by gravity, drill string mechanics and interaction of the drill string with the borehole.
means to filter out near bit moments caused by gravity, drill string mechanics and interaction of the drill string with the borehole.
19. A system according to Claim 17 further comprising:
means to detect the presence of the formation interface.
means to detect the presence of the formation interface.
20. A system according to Claim 19 wherein said means to detect the presence of the formation interface is a downhole accelerometer sensitive to the formation characteristics.
21. A system according to Claim 19 wherein said meant to detect the presence of the formation interface is a downhole formation evaluation sensor.
22. A system according to Claim 21 wherein said downhole formation evaluation sensor is a gamma ray sensor.
23. A system according to Claim 21 wherein said downhole formation evaluation sensor is a neutron porosity sensor.
24. A system according to Claim 21 wherein said downhole formation evaluation sensor is a gamma-gamma density sensor.
25. A system according to Claim 21 wherein said downhole formation evaluation sensor is a formation resistivity sensor.
26. A system according to Claim 21 wherein said downhole formation evaluation sensor is formed by a combination of sensor devices.
27. A system according to Claim 17 wherein said means to measure the orientation of said bit bending moments comprise oriented magnetometers.
28. A system according to Claim 17 wherein said means to determine presence and dip of a formation interface comprises a microprocessor located downhole in an equipment sub.
29. A system according to Claim 28 wherein said micro-processor further comprises memory storage means.
30. A system according to Claim 28 wherein said micro-processor further controls means to transmit to the surface information about the formation interface.
31. A system according to Claim 19 wherein said means to detect the presence of the formation interface utilizes a measurement system that provides a normalized drilling rate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/824,186 US4747303A (en) | 1986-01-30 | 1986-01-30 | Method determining formation dip |
| US824,186 | 1986-01-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1270113A true CA1270113A (en) | 1990-06-12 |
Family
ID=25240816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000519304A Expired - Lifetime CA1270113A (en) | 1986-01-30 | 1986-09-29 | Method for determining formation dip |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4747303A (en) |
| CA (1) | CA1270113A (en) |
| GB (1) | GB2186083B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4903245A (en) * | 1988-03-11 | 1990-02-20 | Exploration Logging, Inc. | Downhole vibration monitoring of a drillstring |
| US4833914A (en) * | 1988-04-29 | 1989-05-30 | Anadrill, Inc. | Pore pressure formation evaluation while drilling |
| US5064006A (en) * | 1988-10-28 | 1991-11-12 | Magrange, Inc | Downhole combination tool |
| US5230387A (en) * | 1988-10-28 | 1993-07-27 | Magrange, Inc. | Downhole combination tool |
| US5220963A (en) * | 1989-12-22 | 1993-06-22 | Patton Consulting, Inc. | System for controlled drilling of boreholes along planned profile |
| US5133418A (en) * | 1991-01-28 | 1992-07-28 | Lag Steering Systems | Directional drilling system with eccentric mounted motor and biaxial sensor and method |
| US5200705A (en) * | 1991-10-31 | 1993-04-06 | Schlumberger Technology Corporation | Dipmeter apparatus and method using transducer array having longitudinally spaced transducers |
| WO1993012319A1 (en) * | 1991-12-09 | 1993-06-24 | Patton Bob J | System for controlled drilling of boreholes along planned profile |
| US5720354A (en) * | 1996-01-11 | 1998-02-24 | Vermeer Manufacturing Company | Trenchless underground boring system with boring tool location |
| WO1998017894A2 (en) * | 1996-10-22 | 1998-04-30 | Baker Hughes Incorporated | Drilling system with integrated bottom hole assembly |
| GB2334108B (en) * | 1996-10-22 | 2001-03-21 | Baker Hughes Inc | Drilling system with integrated bottom hole assembly |
| CA2550405C (en) * | 2003-12-19 | 2009-09-01 | Pushkar Nath Jogi | Method and apparatus for enhancing directional accuracy and control using bottomhole assembly bending measurements |
| US7243719B2 (en) * | 2004-06-07 | 2007-07-17 | Pathfinder Energy Services, Inc. | Control method for downhole steering tool |
| US7350568B2 (en) * | 2005-02-09 | 2008-04-01 | Halliburton Energy Services, Inc. | Logging a well |
| US8286729B2 (en) * | 2008-02-15 | 2012-10-16 | Baker Hughes Incorporated | Real time misalignment correction of inclination and azimuth measurements |
| US9043152B2 (en) * | 2011-08-08 | 2015-05-26 | Baker Hughes Incorporated | Realtime dogleg severity prediction |
| US11920460B2 (en) * | 2021-12-08 | 2024-03-05 | Saudi Arabian Oil Company | Identifying formation layer tops while drilling a wellbore |
| US20230296013A1 (en) * | 2022-03-18 | 2023-09-21 | Halliburton Energy Services, Inc. | In-bit strain measurement for automated bha control |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2930137A (en) * | 1954-08-04 | 1960-03-29 | Jan J Arps | Earth borehole crookedness detection and indication |
| US3077670A (en) * | 1959-09-23 | 1963-02-19 | Pgac Dev Company | Method and apparatus for making a dipmeter survey of a borehole |
| US3186222A (en) * | 1960-07-28 | 1965-06-01 | Mccullough Tool Co | Well signaling system |
| US3255353A (en) * | 1962-12-21 | 1966-06-07 | Serge A Scherbatskoy | Apparatus for nuclear well logging while drilling |
| US3626482A (en) * | 1968-10-30 | 1971-12-07 | Aquitaine Petrole | Method and apparatus for measuring lithological characteristics of rocks |
| US4445578A (en) * | 1979-02-28 | 1984-05-01 | Standard Oil Company (Indiana) | System for measuring downhole drilling forces |
| US4479564A (en) * | 1979-04-12 | 1984-10-30 | Schlumberger Technology Corporation | System and method for monitoring drill string characteristics during drilling |
| US4452075A (en) * | 1979-10-29 | 1984-06-05 | Conoco Inc. | Push drill guidance indication apparatus |
| US4324297A (en) * | 1980-07-03 | 1982-04-13 | Shell Oil Company | Steering drill string |
-
1986
- 1986-01-30 US US06/824,186 patent/US4747303A/en not_active Expired - Fee Related
- 1986-09-29 CA CA000519304A patent/CA1270113A/en not_active Expired - Lifetime
- 1986-10-28 GB GB08625726A patent/GB2186083B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2186083B (en) | 1989-01-25 |
| GB2186083A (en) | 1987-08-05 |
| GB8625726D0 (en) | 1986-12-03 |
| US4747303A (en) | 1988-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1270113A (en) | Method for determining formation dip | |
| US5646611A (en) | System and method for indirectly determining inclination at the bit | |
| US4662458A (en) | Method and apparatus for bottom hole measurement | |
| US7650241B2 (en) | Use of the dynamic downhole measurements as lithology indicators | |
| US6769497B2 (en) | Use of axial accelerometer for estimation of instantaneous ROP downhole for LWD and wireline applications | |
| EP1623090B1 (en) | Formation testing apparatus and method for optimizing draw down | |
| US7316278B2 (en) | Method for determining drilling malfunction by correlation of drilling operating parameters and drilling response parameters | |
| US5513528A (en) | Logging while drilling method and apparatus for measuring standoff as a function of angular position within a borehole | |
| US4599904A (en) | Method for determining borehole stress from MWD parameter and caliper measurements | |
| US20090294174A1 (en) | Downhole sensor system | |
| CN1756893B (en) | Method and system for cause-effect time lapse analysis | |
| NO338415B1 (en) | Measurement-Under-Drilling Unit and Method Using Real-Time Tool Area Oriented Measurements | |
| GB2164744A (en) | Apparatus and method for estimating formation characteristics of exposed bottomhole formation | |
| US6708781B2 (en) | System and method for quantitatively determining variations of a formation characteristic after an event | |
| US7302346B2 (en) | Data logging | |
| US4981036A (en) | Method of determining the porosity of an underground formation being drilled | |
| US7921730B2 (en) | Downhole rock scratcher and method for identifying strength of subsurface intervals | |
| US5010765A (en) | Method of monitoring core sampling during borehole drilling | |
| EP0857855B1 (en) | Downhole directional measurement system | |
| AU770556B2 (en) | Wellbore caliper measurement method using measurements from a gamma-gamma density instrument | |
| GB2270385A (en) | Method for determining weight on bit | |
| Denney | Dynamic Depth Correction To Reduce Depth Uncertainty and Improve MWD/LWD Log Quality | |
| Thomson et al. | Enhanced geological modelling through advances in logging and interpretation of inseam boreholes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |