EP2488722A1 - Estimation de contraintes de formation à l'aide de profils radiaux de trois modules de cisaillement - Google Patents

Estimation de contraintes de formation à l'aide de profils radiaux de trois modules de cisaillement

Info

Publication number
EP2488722A1
EP2488722A1 EP09847452A EP09847452A EP2488722A1 EP 2488722 A1 EP2488722 A1 EP 2488722A1 EP 09847452 A EP09847452 A EP 09847452A EP 09847452 A EP09847452 A EP 09847452A EP 2488722 A1 EP2488722 A1 EP 2488722A1
Authority
EP
European Patent Office
Prior art keywords
shear
horizontal
dipole
formation
borehole
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.)
Withdrawn
Application number
EP09847452A
Other languages
German (de)
English (en)
Other versions
EP2488722A4 (fr
Inventor
Bikash K. Sinha
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Services Petroliers Schlumberger SA
Prad Research and Development Ltd
Schlumberger Technology BV
Schlumberger Holdings Ltd
Original Assignee
Services Petroliers Schlumberger SA
Prad Research and Development Ltd
Schlumberger Technology BV
Schlumberger Holdings Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Services Petroliers Schlumberger SA, Prad Research and Development Ltd, Schlumberger Technology BV, Schlumberger Holdings Ltd filed Critical Services Petroliers Schlumberger SA
Publication of EP2488722A1 publication Critical patent/EP2488722A1/fr
Publication of EP2488722A4 publication Critical patent/EP2488722A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK 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
    • E21B49/006—Measuring wall stresses in the borehole
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/40—Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging
    • G01V1/44—Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging using generators and receivers in the same well
    • G01V1/48—Processing data
    • G01V1/50—Analysing data

Definitions

  • the invention is generally related to analysis of subterranean formations, and more particularly to estimating formation stresses using radial profiles of three shear moduli.
  • Formation stresses can affect geophysical prospecting and development of oil and gas reservoirs. For example, overburden stress, maximum and minimum horizontal stresses, pore pressure, wellbore pressure and rock strength can be used to produce a failure model to aid in well planning, wellbore stability calculations and reservoir management. It is known that elastic wave velocities change as a function of prestress in a propagating medium. For example, sonic velocities in porous rocks change as a function of effective prestress. However, estimating formation stresses based on velocity can be problematic because of influences on the horizontal shear modulus C 6 6- For example, the horizontal shear modulus C 6 e is reduced in the presence of horizontal fluid mobility in a porous reservoir.
  • the tube wave slowness decreases by about 2 to 3% in the presence of fluid mobility, resulting in a decrease in C 6 e by about 4 to 6%.
  • the horizontal shear modulus C 6 e is increased in the presence of high clay content in a shale interval. Consequently, it is difficult to accurately estimate the ratio of vertical to horizontal stress ratios without compensating for the changes in
  • Various devices are known for measuring formation characteristics based on sonic data.
  • Mechanical disturbances are used to establish elastic waves in earth formations surrounding a borehole, and properties of the waves are measured to obtain information about the formations through which the waves have propagated.
  • compressional, shear and Stoneley wave information such as velocity (or its reciprocal, slowness) in the formation and in the borehole can help in evaluation and production of hydrocarbon resources.
  • Sonic Scanner® from Schlumberger.
  • piezoelectric source is configured as either a monopole or a dipole source.
  • the source bandwidth typically ranges from a 0.5 to 20 kHz.
  • a monopole source primarily generates the lowest-order axisymmetric mode, also referred to as the Stoneley mode, together with compressional and shear headwaves.
  • a dipole source primarily excites the lowest-order flexural borehole mode together with compressional and shear headwaves.
  • the headwaves are caused by the coupling of the transmitted acoustic energy to plane waves in the formation that propagate along the borehole axis.
  • An incident compressional wave in the borehole fluid produces critically refracted compressional waves in the formation. Those refracted along the borehole surface are known as compressional headwaves.
  • the critical incidence angle ⁇ , sin "1 (V//V c ), where V/ is the compressional wave speed in the borehole fluid; and V 0 is the compressional wave speed in the formation.
  • V/ the compressional wave speed in the borehole fluid
  • V 0 the compressional wave speed in the formation.
  • compressional and shear headwaves can be generated by a monopole source placed in a fluid-filled borehole for determining the formation compressional and shear wave speeds. It is known that refracted shear headwaves cannot be detected in slow formations (where the shear wave velocity is less than the borehole-fluid compressional velocity) with receivers placed in the borehole fluid. In slow formations, formation shear velocities are obtained from the low-frequency asymptote of flexural dispersion. There are standard processing techniques for the estimation of formation shear velocities in either fast or slow formations from an array of recorded dipole waveforms. A different type of tool described in U.S. Patent No.
  • estimating stress in a formation in which a borehole is present comprises: determining radial profiles of Stoneley, fast dipole shear and slow dipole shear slownesses; estimating maximum and minimum horizontal stresses by inverting differences in far-field shear moduli with difference equations obtained from radial profiles of dipole shear moduli C44 and C55, and borehole stresses proximate to the borehole; and producing an indication of the maximum and minimum horizontal stresses in tangible form.
  • apparatus for estimating stress in a formation in which a borehole is present comprises: at least one acoustic sensor that provides radial profiles of Stoneley, fast dipole shear and slow dipole shear slownesses; processing circuitry that estimates maximum and minimum horizontal stresses by inverting differences in far-field shear moduli with difference equations obtained from radial profiles of dipole shear moduli C 44 and C 55 , and borehole stresses proximate to the borehole; and an output that produces an indication of the maximum and minimum horizontal stresses in tangible form.
  • Figure 1 is a schematic diagram of a borehole in a formation subject to the far-field principal stresses.
  • Figure 2 is a schematic diagram of a borehole of radius "a" subject to formation stresses in a poroelastic formation with pore pressure P P and wellbore pressure P w .
  • Figure 3 illustrates a logging tool for estimating formation stresses using radial profiles of three shear moduli.
  • Figure 4 is a flow diagram illustrating steps of a method in accordance with an embodiment of the invention.
  • Figure 5 illustrates radial variation of axial ( ⁇ ZZ), hoop ( ⁇ ), and radial ( ⁇ rr) effective stresses at an azimuth parallel to the maximum horizontal stress direction at a given depth.
  • Figure 6 illustrates radial variation of axial ( ⁇ ZZ), hoop ( ⁇ ), and radial ( ⁇ rr) effective stresses at an azimuth perpendicular to the maximum horizontal stress direction.
  • Figure 7 illustrates fast and slow shear dispersion curves which exhibit a crossing signature together with the lowest-order axisymmetric Stoneley dispersion
  • Figure 9 illustrates an algorithm for solving for the unknowns Ae and ⁇ H/ ⁇ V, which enables determination of SH, and an acoustoelastic coefficient Ae.
  • FIG. 3 illustrates one example of a logging tool (106) used to acquire and analyze data in accordance with an embodiment of the invention.
  • the tool has a plurality of receivers and transmitters.
  • the illustrated logging tool (106) also includes multi-pole transmitters such as crossed dipole transmitters (120, 122) (only one end of dipole (120) is visible in Figure 1 ) and monopole transmitters (109) (close) and (124) (far) capable of exciting compressional, shear, Stoneley, and flexural waves.
  • the logging tool (106) also includes receivers (126), which are spaced apart some distance from the transmitters. Each receiver may include multiple hydrophones mounted azimuthally at regular intervals around the circumference of the tool. Other configurations, such as a Digital Sonic Imaging (DSI) tool with four receivers at each of eight receiver stations, or incorporating other multi-pole sources such as
  • DSI Digital Sonic Imaging
  • receivers and transmitters are also possible.
  • the use of a plurality of receivers and transmitters results in improved signal quality and adequate extraction of the various borehole signals over a wide frequency band
  • the distances, number and types of receivers and transmitters shown in this embodiment are merely one possible configuration, and should not be construed as limiting the invention.
  • the subsurface formation (102) is traversed by a borehole (104) which may be filled with drilling fluid or mud.
  • the logging tool (106) is suspended from an armored cable (108) and may have optional centralizers (not shown).
  • the cable (108) extends from the borehole (104) over a sheave wheel (1 10) on a derrick (1 12) to a winch forming part of surface equipment, which may include an analyzer unit (1 14).
  • Well known depth gauging equipment (not shown) may be provided to measure cable displacement over the sheave wheel (1 10).
  • the tool (106) may include any of many well known devices to produce a signal indicating tool orientation.
  • Processing and interface circuitry within the tool (106) amplifies, samples and digitizes the tool's information signals for transmission and communicates them to the analyzer unit (1 14) via the cable (108). Electrical power and control signals for coordinating operation of the tool (106) may be generated by the analyzer unit (1 14) or some other device, and communicated via the cable (108) to circuitry provided within the tool (106).
  • the surface equipment includes a processor subsystem (1 16) (which may include a microprocessor, memory, clock and timing, and input/output functions-not separately shown), standard peripheral equipment (not separately shown), and a recorder (1 18).
  • Figure 4 is a flow diagram that illustrates a method of estimating formation stresses using radial profiles of three shear moduli.
  • a depth interval characterized by relatively uniform lithology is selected for evaluation of stresses.
  • Monopole and cross-dipole sonic data is then obtained with the tool (106, Figure 3) over the selected interval, as indicated by step (400).
  • the monopole and cross-dipole data, density (p f> ) far field velocity (V f) , and borehole radius (a) are used to determine radial profiles of Stoneley, fast dipole shear slowness and slow dipole shear slowness as indicated by step (402).
  • Formation bulk density (p b ) obtained in step (404) is then used to calculate radial profiles of the three shear moduli (C44, C55, C66) as shown in step (406). The next step is selected based on the result of the shear moduli calculation.
  • ⁇ C 55 is obtained from the fast-dipole shear slowness from sonic data acquired by a dipole transmitter aligned parallel to the X r direction and borehole parallel to the X 3 -direction; the quantities C 55 , ⁇ , and v are the linear elastic moduli, whereas Ci 44 and Ci 55 are the formation nonlinear constants in the chosen reference state; and ⁇ 3 3, ⁇ n , and Aa 22 ,
  • ⁇ C 44 is obtained from the slow-dipole shear slowness from sonic data acquired by a dipole transmitter aligned parallel to the X 2 -direction and borehole parallel to the X 3 -direction;
  • ⁇ C 6 6 is obtained from the Stoneley shear slowness dispersion from sonic data acquired by a monopole transmitter at a chosen depth of interest.
  • Step (408) includes two component calculations that are made with the aid of overburden stress (Sv), wellbore pressure (P w ), pore pressure (P P ), Biot coefficient ⁇ , and borehole radius (a) data, obtained in step (410).
  • a first component calculation is to form two difference equations using the far-field shear moduli C44, C55, and C66.
  • equations (13)-(15) yield difference equations in the effective shear moduli in terms of differences in the principal stress magnitudes through an acoustoelastic coefficient defined in terms of formation nonlinear constants referred to a chosen reference state and for a given formation lithology.
  • the following three equations relate changes in the shear moduli to corresponding changes in the effective principal stresses in a homogeneously stressed formation as would be the case in the far-field, sufficiently away from the borehole surface:
  • ⁇ 3 3, ⁇ n , and Ao 22 denote changes in the effective overburden, maximum horizontal, and minimum horizontal stresses, respectively;
  • Equation (13), (14), and (15) can be expressed in terms of the principal stress parameters ⁇ H , ⁇ h , and ⁇ v as follows:
  • Equation (34) can be rewritten in a compact form shown below
  • Equation (39) can be rewritten in a compact form as follows:
  • SHmax, Shmin, and an acoustoelastic coefficient Ae are calculated in step (414).
  • the acoustoelastic parameter Ae is calculated as a function the stress ratio ⁇ H / ⁇ v using equation (28).
  • ⁇ h / ⁇ v is calculated in terms of ⁇ H / ⁇ v using equation (30).
  • True Ae is calculated in terms of C 55 , C 44 , ⁇ H , and ⁇ h using equation (18).
  • A1 and A2 are calculated from equations (45) and (46).
  • Ae is again calculated from equation (27).
  • step (416) is used.
  • An algorithm is then used to solve for the unknowns Ae and the effective stress ratio ⁇ H / ⁇ v , as indicated by step (418), which enables determination of the horizontal stress magnitude SH, and an acoustoelastic coefficient Ae, as indicated by step (420).
  • Figure 9 shows a workflow for implementing necessary corrections in the shear modulus C 6 e in the presence of either fluid mobility in a reservoir or structural anisotropy in shales.
  • Estimation of formation stress magnitudes (910) using the three shear moduli requires compensation (912) for fluid mobility effects in a reservoir and structural anisotropy effects in overburden or underburden shales as calculated in step (900).
  • Algorithm I is to estimate the horizontal to overburden stress ratio in a reasonably uniform depth interval using differences in the compressional and shear slownesses at two depths within the chosen interval.
  • Algorithm II is to estimate the horizontal to overburden stress ratio using the two far-field shear moduli (C 44 and C ⁇ ), and radial profile of the dipole shear modulus (C 44 ). This algorithm can be applied in depth intervals that are axially heterogeneous insofar as the difference equations use shear moduli at the same chosen depth.
  • C 1 55 is one of the three nonlinear constants referred to the chosen depth interval.
  • An incremental change in the effective stiffness ⁇ C 6 6 can be expressed in terms of changes in the effective vertical stress between two depths in a reasonably uniform lithology interval
  • Ci 44 is another nonlinear constants referred to the chosen depth interval.
  • An incremental change in the effective stiffness ⁇ C33 can be expressed in terms of changes in the effective vertical stress between two depths in a reasonably uniform lithology interval
  • Equations (50), (51 ), and (52) are used to calculate the three nonlinear constants (Cm , Ci 44 , Ci 55 ) in the chosen depth interval. These nonlinear constants together with linear constants enable determination of the stress coefficients of velocities in the chosen depth interval.
  • a second step is to use general 3D-equations relating changes in the effective stresses to corresponding changes in the effective elastic moduli and estimate the unknown stress magnitudes SHmax and Shmin in the chosen depth interval where the three nonlinear constants have been estimated.
  • ⁇ C 55 is obtained from the fast-dipole shear slowness and formation bulk density at the top and bottom of the interval.
  • ⁇ C 44 is obtained from the slow-dipole shear slowness and formation bulk density at the top and bottom of the interval.
  • ⁇ C 6 e is obtained from the Stoneley shear slowness dispersion and formation bulk density at the top and bottom of the interval.
  • index A and B denote the top and bottom of the chosen depth interval.
  • Algorithm Il is a preferred technique in environments where the formation exhibits azimuthal isotropy in cross-dipole dispersions implying that horizontal stresses are nearly the same at all azimuths. Further, this technique is more suitable for formations where lithology is rapidly changing with depth than Algorithm I. The presence of a borehole causes near-wellbore stress distributions that can be described by equations (1 ) through (4).
  • V s denotes the shear velocity at different radial positions obtained from the Dipole Radial Profiling (DRP) of shear velocity.
  • DRP Dipole Radial Profiling

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  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Geophysics (AREA)
  • Acoustics & Sound (AREA)
  • Fluid Mechanics (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)

Abstract

Selon l'invention, des contraintes horizontales maximales et minimales, et un rapport de contraintes horizontales à surchargées, sont estimés à l'aide de profils radiaux de modules de cisaillement. Une inversion permet l'estimation de contraintes horizontales maximales et minimales à l'aide de profils radiaux de trois modules de cisaillement associés à un ensemble orthogonal d'axes définis par les trois directions de contraintes principales. Des différences dans les modules de cisaillement de champ lointain sont inversées, avec deux équations de différence obtenues à partir des profils radiaux des modules de cisaillement dipolaires C44 et C55, et de contraintes de trou de forage dans la région proche de forage de puits. Le rapport de contraintes horizontales à surchargées est estimé à l'aide de différences dans les lenteurs de cisaillement dipolaire de compression, et de cisaillement de Stoneley à deux profondeurs dans le même intervalle lithologique où la formation présente une isotropie azimutale dans des dispersions dipolaires croisées, ce qui implique que des contraintes horizontales sont quasiment les mêmes à tous les azimuts. Le rapport de contraintes surchargées à horizontales dans une formation avec une hétérogénéité axiale peut également être estimé à l'aide du module de cisaillement de Stoneley de champ lointain C66 et du module de cisaillement dipolaire C55 avec la variation radiale du module de cisaillement dipolaire C55 provoquée par des concentrations de contraintes de voisinage de forage de puits.
EP09847452.1A 2009-07-20 2009-07-20 Estimation de contraintes de formation à l'aide de profils radiaux de trois modules de cisaillement Withdrawn EP2488722A4 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2009/051146 WO2011010989A1 (fr) 2009-07-20 2009-07-20 Estimation de contraintes de formation à l'aide de profils radiaux de trois modules de cisaillement

Publications (2)

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EP2488722A1 true EP2488722A1 (fr) 2012-08-22
EP2488722A4 EP2488722A4 (fr) 2017-11-08

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EP09847452.1A Withdrawn EP2488722A4 (fr) 2009-07-20 2009-07-20 Estimation de contraintes de formation à l'aide de profils radiaux de trois modules de cisaillement

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EP (1) EP2488722A4 (fr)
BR (1) BR112012001198B1 (fr)
CA (1) CA2731780C (fr)
GB (1) GB2484247B (fr)
MX (1) MX2012000832A (fr)
WO (1) WO2011010989A1 (fr)

Cited By (1)

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CN112965100A (zh) * 2021-02-18 2021-06-15 中海油田服务股份有限公司 一种确定偶极声源发射频率的方法及装置

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WO2017003517A1 (fr) * 2015-06-30 2017-01-05 Halliburton Energy Services, Inc. Correction des effets de déviation et de dispersion sur des mesures de diagraphie acoustique de puits déviés dans des formations stratifiées
US10408054B2 (en) * 2015-08-25 2019-09-10 Conocophillips Company Method for estimating stress magnitude
CN114622902A (zh) * 2020-12-11 2022-06-14 中国石油天然气股份有限公司 全剖面水平主应力测量方法及装置
CN113703047B (zh) * 2021-09-18 2024-04-09 中国石油大学(华东) 一种预测水平地应力差的方法、装置及存储介质

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US5838633A (en) * 1997-01-27 1998-11-17 Schlumberger Technology Corporation Method for estimating formation in-situ stress magnitudes using a sonic borehole tool
US6098021A (en) * 1999-01-15 2000-08-01 Baker Hughes Incorporated Estimating formation stress using borehole monopole and cross-dipole acoustic measurements: theory and method
US6351991B1 (en) * 2000-06-05 2002-03-05 Schlumberger Technology Corporation Determining stress parameters of formations from multi-mode velocity data
US6611761B2 (en) * 2000-12-19 2003-08-26 Schlumberger Technology Corporation Sonic well logging for radial profiling
US6904365B2 (en) * 2003-03-06 2005-06-07 Schlumberger Technology Corporation Methods and systems for determining formation properties and in-situ stresses
US7042802B2 (en) * 2003-09-18 2006-05-09 Schlumberger Technology Corporation Determination of stress characteristics of earth formations
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112965100A (zh) * 2021-02-18 2021-06-15 中海油田服务股份有限公司 一种确定偶极声源发射频率的方法及装置

Also Published As

Publication number Publication date
BR112012001198B1 (pt) 2019-01-15
GB201201975D0 (en) 2012-03-21
GB2484247B (en) 2015-06-03
GB2484247A (en) 2012-04-04
BR112012001198A2 (pt) 2016-03-01
WO2011010989A1 (fr) 2011-01-27
CA2731780C (fr) 2016-02-16
CA2731780A1 (fr) 2011-01-27
MX2012000832A (es) 2012-04-11
EP2488722A4 (fr) 2017-11-08

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