CN114417587A - Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state - Google Patents

Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state Download PDF

Info

Publication number
CN114417587A
CN114417587A CN202210030527.3A CN202210030527A CN114417587A CN 114417587 A CN114417587 A CN 114417587A CN 202210030527 A CN202210030527 A CN 202210030527A CN 114417587 A CN114417587 A CN 114417587A
Authority
CN
China
Prior art keywords
pressure
stratum
depth
pore pressure
formation
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.)
Granted
Application number
CN202210030527.3A
Other languages
Chinese (zh)
Other versions
CN114417587B (en
Inventor
熊晓军
段文博
童浩
罗海龙
许志远
张正鹏
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.)
Chengdu Univeristy of Technology
Original Assignee
Chengdu Univeristy of Technology
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 Chengdu Univeristy of Technology filed Critical Chengdu Univeristy of Technology
Priority to CN202210030527.3A priority Critical patent/CN114417587B/en
Publication of CN114417587A publication Critical patent/CN114417587A/en
Application granted granted Critical
Publication of CN114417587B publication Critical patent/CN114417587B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • 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
    • E21B49/08—Obtaining fluid samples or testing fluids, in boreholes or wells
    • E21B49/087—Well testing, e.g. testing for reservoir productivity or formation parameters
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q10/00—Administration; Management
    • G06Q10/04—Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem"
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q50/00—Information and communication technology [ICT] specially adapted for implementation of business processes of specific business sectors, e.g. utilities or tourism
    • G06Q50/02—Agriculture; Fishing; Forestry; Mining
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Business, Economics & Management (AREA)
  • Theoretical Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Economics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Human Resources & Organizations (AREA)
  • Strategic Management (AREA)
  • General Physics & Mathematics (AREA)
  • Marketing (AREA)
  • Tourism & Hospitality (AREA)
  • Geology (AREA)
  • General Business, Economics & Management (AREA)
  • Primary Health Care (AREA)
  • Evolutionary Computation (AREA)
  • Game Theory and Decision Science (AREA)
  • Agronomy & Crop Science (AREA)
  • Animal Husbandry (AREA)
  • Marine Sciences & Fisheries (AREA)
  • Development Economics (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Operations Research (AREA)
  • Computer Hardware Design (AREA)
  • Entrepreneurship & Innovation (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Quality & Reliability (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

The invention provides a stratum pore pressure prediction method suitable for a compact clastic rock stratum in a low-pressure state, the method is characterized in that according to the geological cause background that most of overburden stratum pressure is converted into effective stress on rock framework particles due to secondary sediment burial depth of a geologic body, the change of the formation pore fluid pressure is characterized by adopting the volume change rate of the formation pore fluid by combining the dynamic balance characteristics of the formation pore pressure and the rock framework stress, the formation pore pressure prediction formula suitable for the compact clastic rock stratum in the low pressure state is deduced, the prediction of the formation pore pressure of the compact clastic rock stratum in the low pressure state is carried out based on the prediction formula, the method is more complete in theory, and the difficulty of predicting the formation pore pressure of the compact clastic rock formation under the condition of less rock physical parameters is effectively overcome by only adopting the porosity parameter for calculation.

Description

Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state
Technical Field
The invention relates to stratum pore pressure prediction in the technical field of oil and gas field exploration, in particular to a stratum pore pressure prediction method suitable for a compact clastic rock stratum in a low-pressure state.
Background
In recent years, the development of unconventional oil and gas exploration is becoming a global focus of attention. The dense gas is an unconventional oil and gas resource, and the well drilling and exploitation of the dense gas are also concerned. For tight gas reservoirs, the formation pore pressure characteristics are very complex, including both high and low pressure states: under high pressure, a conventional method is adopted, an Eaton method for comparing the acoustic wave time difference with the normal compaction trend line is generally adopted, a Filliptone method for the seismic layer velocity is adopted, and various methods such as a porosity and equivalent depth method for well logging data are adopted to achieve prediction accuracy; the reason for the abnormal low pressure is that the geological body is subjected to secondary deposition and burial depth due to the long-time stagnation of the stratum, so that most of the overlying stratum pressure is born by the stress of a rock framework, and the abnormal low pressure is caused, and the characteristic can not be used for predicting the stratum pore pressure through a compaction theory.
At present, few methods for predicting formation pore pressure in low pressure state are published, and a representative method published in the publication is the method of xuanming and the like (study on abnormal low pressure cause mechanism in the two-pot basin, "university of petroleum in china," pages 2007, 13-18). The method aims at the abnormal low pressure of the compact clastic rock, and adopts the assumption that the volume change of the underground geologic body is approximately equal to the volume change of the pore fluid:
Figure BDA0003466276430000011
wherein V is the total volume of the rock; povOverburden pressure, unit: MPa; pfIs the formation pore pressure, in units: MPa; k is the bulk modulus, in units: MPa;
Figure BDA0003466276430000012
is porosity; kfIs the coefficient of compression of the fluid, in units：MPa。
The formula 1 is simplified to obtain
Figure BDA0003466276430000013
The method needs accurate transverse wave test data when calculating the volume modulus K, but an actual oil and gas well often lacks accurate transverse wave test data, and an empirical formula is usually used for fitting to obtain the transverse wave velocity, so that the method is not high in accuracy of predicting the formation pore pressure.
Disclosure of Invention
(one) analysis of the advantages of the present invention over conventional techniques
The method is based on the assumption that the volume change rate of the formation pore fluid represents the pressure change of the formation pore fluid, starts from Terzaghi effective stress theorem, adopts the volume change rate of the formation pore fluid to represent the pressure change of the formation pore fluid, and deduces a formation pore pressure prediction formula which is based on porosity parameters and is suitable for the compact clastic rock formation in a low-pressure state. The formula calculates the formation pore pressure through the porosity parameter without calculating the overlying formation pressure and the bulk modulus, and reduces errors caused by lack of accurate transverse wave test data and near-surface density, so that the method can be better suitable for prediction of the formation pore pressure in different research areas under a low-pressure state compared with the formula 2.
(II) core content of the invention
According to the geological cause background that most of overburden stratum pressure is converted into effective stress on rock skeleton particles due to secondary sediment burial depth of a geologic body, the change of the stratum pore fluid pressure is characterized by adopting the volume change rate of the stratum pore fluid by combining the dynamic balance characteristics of the stratum pore pressure and the rock skeleton stress, the stratum pore pressure prediction formula applicable to the compact clastic rock stratum in the low-pressure state is deduced, the stratum pore pressure prediction of the compact clastic rock stratum in the low-pressure state is carried out based on the prediction formula, the method is more complete in theory, only the porosity parameter is adopted for calculation, and the problem of stratum pore pressure prediction of the compact clastic rock stratum under the condition that the physical parameters of the rock are few is effectively solved.
The derivation process of a core calculation formula suitable for predicting the formation pore pressure of the compact clastic rock formation in a low-pressure state is as follows:
based on Terzaghi effective stress theorem, the relation among the effective stress of the rock, the overburden pressure and the formation pore pressure,
Pov＝σ+Pf (3)
in the formula, PovIs overburden pressure, in units: MPa; pfIs the formation pore fluid pressure, in units: MPa; σ is the rock skeletal stress of the formation, in units: MPa.
When the earth formation is in a normal state of compaction,
Pf＝Pw (4)
in the formula, PwHydrostatic pressure, unit: MPa.
For a compact clastic rock stratum, the rock skeleton stress of the stratum in a low-pressure state is sigma1Comparing and analyzing the variation of the stress of the rock framework in a low-pressure state and a normal compaction state,
Δσ＝σ1-σ0 (5)
σ in equation 50Is the stress of the rock skeleton in a normal compaction state.
According to the formula 3 and the formula 4, the method is obtained
σ1＝Pov-Pf (6)
σ0＝Pov-Pw (7)
Substituting the formula 6 and the formula 7 into the formula 5 to obtain
Δσ＝Pw-Pf (8)
Next, the amount of change in formation pore fluid pressure in the low pressure state is analyzed in comparison with the normal compaction state.
Based on the assumption that the volume change of the underground geologic body is approximately equal to the volume change of the pore fluid in the abnormal low-pressure state under the conditions of Schenming, et al (research on the mechanism of abnormal low pressure cause of the two-basin-connected field, journal of the university of China (Nature science edition), 2007, pages 13-18), the invention creatively adopts the volume change rate of the formation pore fluid to indicate the change of the pressure of the formation pore fluid,
Figure BDA0003466276430000031
in the formula, PwHydrostatic pressure, which represents the formation pore fluid pressure at normal compaction conditions; Δ VrIs the volume change of the pore fluid of the rock, and V is the total volume of the rock.
Based on the theory of methods of Schenming et al (the mechanism of abnormal low pressure cause of the two-basin field, book of university of Petroleum in China (Nature science), 2007, pp. 13-18),
Figure BDA0003466276430000041
substituting the formula 10 into the formula 9 to obtain
Figure BDA0003466276430000042
When the depth of the target layer is not changed, namely the low-pressure cause is not a structural cause, the overlying stratum pressure of the target layer is not changed in a normal compaction state and a low-pressure state; at this time, the decrease of the formation pore pressure and the increase of the effective stress are in dynamic balance by formula 5,
Δσ＝ΔPf (12)
substituting the formula 8 and the formula 10 into the formula 11 to obtain
Figure BDA0003466276430000043
Equation 13 is the core calculation equation for the formation pore pressure prediction for tight clastic formations at low pressure derived by the present invention.
Drawings
FIG. 1 is a diagram of the prediction of formation pore pressure based on logging data of a tight sandstone development area of the group of the temple in a certain area of Sichuan calculated by the method of the invention.
Detailed Description
Example 1
A stratum pore pressure prediction method suitable for a compact clastic rock stratum in a low-pressure state is characterized in that the concrete steps of predicting the stratum pore pressure of a target interval based on logging data comprise:
step 1, inputting porosity POR and natural gamma GR logging data and time-depth relation of a research area, depths of a top interface and a bottom interface of a target layer, data of an actually measured pressure point of the target layer and an actually measured pressure value Pf_realAnd depth Hreal；
Step 2, calculating intermediate parameters of the target interval and a fluid compression coefficient K based on the logging data of the actually measured pressure pointf
Figure BDA0003466276430000051
In the formula (I), the compound is shown in the specification,
Figure BDA0003466276430000052
the porosity of the measured pressure point is obtained;
step 3, circularly calculating the depth of each depth point of the target interval,
Figure BDA0003466276430000053
wherein i ranges from 0 to N, H0Is the depth of the top interface of the target interval, H1Is the depth of the bottom interface of the target interval;
step 4, calculating the current depth point H of the target layer sectioniPore pressure P of the formationf_i
Figure BDA0003466276430000054
In the formula (I), the compound is shown in the specification,
Figure BDA0003466276430000055
porosity at the ith depth point;
step 5, calculating the current depth point H of the target layer sectioniPressure coefficient P ofcoef_i，
Pcoef_i＝Pf_i/(0.0098*Hi) (17)
In the formula, Pf_iIs a depth point HiThe formation pore pressure of;
and 6, calculating from the condition that i is 0, sequentially increasing the value of i, and repeating the steps 4 to 5 until the circulation is ended when i is N, so that the formation pore pressure and the formation pore pressure coefficient of the target interval in the abnormal low-pressure state are obtained.
Example 2
In order to illustrate the effectiveness and the advancement of the core formula of the invention, a completed well with measured formation pore pressure data is used for analysis and illustration.
Fig. 1 is a diagram of the prediction of the formation pore pressure of a tight sandstone development area of a salxi temple group in a certain area of Sichuan calculated by the method based on logging data, wherein the 1 st column in the diagram is depth, unit: m; column 2 is the acoustic moveout, unit: us/ft; column 3 is porosity, unit: percent; column 4 is natural gamma, unit: an API; column 4 is predicted formation pore pressure, in units: MPa; three actual measurement pressure points are arranged in the target layer section, the prediction errors are respectively 0.3MPa, 0.2MPa and 0.4MPa, and are all less than 0.5MPa, and the prediction precision is met.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (1)

1. A stratum pore pressure prediction method suitable for a compact clastic rock stratum in a low-pressure state is characterized in that the concrete steps of predicting the stratum pore pressure of a target interval based on logging data comprise:
step 1, inputting porosity POR and natural gamma GR logging data and time-depth relation of a research area, depths of a top interface and a bottom interface of a target layer, data of an actually measured pressure point of the target layer and an actually measured pressure value Pf_realAnd depth Hreal；
Step 2, calculating intermediate parameters of the target interval and a fluid compression coefficient K based on the logging data of the actually measured pressure pointf，
Figure FDA0003466276420000011
In the formula (I), the compound is shown in the specification,
Figure FDA0003466276420000012
the porosity of the measured pressure point is obtained;
step 3, circularly calculating the depth of each depth point of the target interval,
Figure FDA0003466276420000013
wherein i ranges from 0 to N, H0Is the depth of the top interface of the target interval, H1Is the depth of the bottom interface of the target interval;
step 4, calculating the current depth point H of the target layer sectioniPore pressure P of the formationf_i，
Figure FDA0003466276420000014
In the formula (I), the compound is shown in the specification,
Figure FDA0003466276420000015
porosity at the ith depth point;
step 5, calculating the current depth point H of the target layer sectioniPressure coefficient P ofcoef_i，
Pcoef_i＝Pf_i/(0.0098*Hi) (4)
In the formula, Pf_iIs a depth point HiThe formation pore pressure of;
and 6, calculating from the condition that i is 0, sequentially increasing the value of i, and repeating the steps 4 to 5 until the circulation is ended when i is N, so that the formation pore pressure and the formation pore pressure coefficient of the target interval in the abnormal low-pressure state are obtained.
CN202210030527.3A 2022-01-12 2022-01-12 Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state Active CN114417587B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210030527.3A CN114417587B (en) 2022-01-12 2022-01-12 Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210030527.3A CN114417587B (en) 2022-01-12 2022-01-12 Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state

Publications (2)

Publication Number Publication Date
CN114417587A true CN114417587A (en) 2022-04-29
CN114417587B CN114417587B (en) 2023-02-28

Family

ID=81272857

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210030527.3A Active CN114417587B (en) 2022-01-12 2022-01-12 Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state

Country Status (1)

Country Link
CN (1) CN114417587B (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130090902A1 (en) * 2010-06-28 2013-04-11 Yao Yao Method and System for Modeling Fractures in Ductile Rock
CN109323954A (en) * 2018-11-15 2019-02-12 中国地质大学（武汉） A kind of predicting method of formation pore pressure for car-bonate rock
CN109458176A (en) * 2018-12-28 2019-03-12 西南石油大学 The prediction technique and its application of carbonate reservoir pressure
CN109509111A (en) * 2017-09-15 2019-03-22 中国石油化工股份有限公司 The prediction technique and system of prospect pit strata pressure
CN109583113A (en) * 2018-12-07 2019-04-05 中国地质大学（武汉） A kind of lithostratigraphy compacting factor and effective pore volume compressibility calculation method
CN111368245A (en) * 2020-03-12 2020-07-03 成都理工大学 Method for quantitatively calculating rock Biot coefficient by considering multiple influence factors

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130090902A1 (en) * 2010-06-28 2013-04-11 Yao Yao Method and System for Modeling Fractures in Ductile Rock
CN109509111A (en) * 2017-09-15 2019-03-22 中国石油化工股份有限公司 The prediction technique and system of prospect pit strata pressure
CN109323954A (en) * 2018-11-15 2019-02-12 中国地质大学（武汉） A kind of predicting method of formation pore pressure for car-bonate rock
CN109583113A (en) * 2018-12-07 2019-04-05 中国地质大学（武汉） A kind of lithostratigraphy compacting factor and effective pore volume compressibility calculation method
CN109458176A (en) * 2018-12-28 2019-03-12 西南石油大学 The prediction technique and its application of carbonate reservoir pressure
CN111368245A (en) * 2020-03-12 2020-07-03 成都理工大学 Method for quantitatively calculating rock Biot coefficient by considering multiple influence factors

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
YIXIN LIU等: "A Distributed Optical Fiber Monitoring Mine Pressure Prediction Model Based on Convolutional Neural Network", 《网页在线公开：HTTPS://IEEEXPLORE.IEEE.ORG/STAMP/STAMP.JSP?TP=&ARNUMBER=9525476》 *
刘震等: "沉积盆地地层孔隙动力学研究进展", 《石油学报》 *
巫芙蓉等: "一种改进的页岩气地震约束多因素孔隙压力预测方法", 《天然气工业》 *
张磊等: "渤海湾盆地南堡凹陷异常压力系统及其形成机理", 《石油与天然气地质》 *
熊晓军等: "一种适用于欠压实成因的地层孔隙流体压力预测技术", 《物探化计算技术》 *

Also Published As

Publication number Publication date
CN114417587B (en) 2023-02-28

Similar Documents

Publication Publication Date Title
CN106951660B (en) Sea facies clastic rock horizontal well reservoir logging interpretation method and device
CN108301825B (en) High-temperature high-pressure reservoir pore pressure analysis method
CN110321595B (en) Fault sealing evaluation method for extracting static quality coefficient by logging
CN104863577A (en) Method for forecasting formation pore pressure by utilizing propagation time of seismic longitudinal waves
CN109509111B (en) Method and system for predicting formation pressure of exploratory well
CN105931125B (en) Method for predicting yield of compact oil staged multi-cluster volume fracturing horizontal well
Yermekov et al. Features of permeability anisotropy accounting in the hydrodynamic model
CN107831540A (en) The direct new method for extracting of reservoir physical parameter
CN111706318B (en) Method for determining distribution condition of residual oil of hypotonic reservoir
CN109458176A (en) The prediction technique and its application of carbonate reservoir pressure
CN112282743A (en) Method for predicting drilling mudstone formation pressure
CN115469374A (en) Crack activity analysis method
CN114417587B (en) Stratum pore pressure prediction method suitable for compact clastic rock stratum in low-pressure state
Stump et al. Consolidation state, permeability, and stress ratio as determined from uniaxial strain experiments on mudstone samples from the Eugene Island 330 Area, offshore Louisiana
CN115586572B (en) Seismic rock physical analysis inversion method for pore parameters and reservoir parameters
CN109339771B (en) Shale hydrocarbon reservoir pore pressure prediction method and system
CN117555029A (en) Single well quantitative division method for geomechanical layer of oil and gas reservoir
CN110244358A (en) Knowledge method is sentenced in oil-gas escape area caused by a kind of structure destruction
CN112433255B (en) Method for dividing reservoir flow units based on nuclear magnetic resonance logging data
CN109917489B (en) Novel method for determining underground pressure-bearing water level
CN111650644B (en) Quantitative prediction method for salt cemented sandstone
CN115586574A (en) Device and method for predicting formation pore pressure based on prestack inversion longitudinal and transverse wave impedance
Worthington et al. Optimizing the value of reservoir simulation through quality-assured initialization
Davies et al. Determination of geomechanical properties of a typical Niger Delta reservoir rock using geophysical well logs
CN110297280B (en) Prediction method for carbonate rock overpressure spatial distribution characteristics

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant