A method for accurately predicting formation pore pressure in the entire well section of an developed old oil field

Abstract

A method for accurately predicting formation pore pressure of the entire well section of an old developed oil field, the method comprising the steps of: obtaining formation pore pressure data of the entire well section of the old developed oil field; calculating the pressure coefficient value of the entire well section of the old developed oil field; obtaining pressure test data of target layers of all adjacent wells in the entire well section of the old developed oil field; screening the pressure test data of target layers of all adjacent wells; calibrating the pressure coefficient value according to the screening result; and obtaining the formation pore pressure value of the entire well section according to the calibration result. The method for accurately predicting formation pore pressure of the entire well section of an old developed oil field provided in the present application adopts the existing seismic velocity, measured pressure data and development dynamic data to comprehensively predict the pressure coefficient of the entire well section of a new well, thereby improving the pressure prediction accuracy of the new well, and on this basis, accurate pressure controlled drilling can be carried out, which not only ensures the safety of drilling and well control, but also lays a solid foundation for the high production and high efficiency of new wells.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield development geology, and in particular relates to a method for accurately predicting formation pore pressure in the entire well section of an old oilfield that has been developed. Background Art

[0002] Formation pore pressure is one of the most important factors to be considered in drilling well control risks. If its value is predicted too high, it will lead to the crushing of oil and gas layers and formation rupture. If it is predicted too low, it may cause underbalanced drilling, resulting in serious well control accidents such as overflow and blowout.

[0003] At present, the main methods for predicting formation pore pressure include seismic layer velocity method, well logging curve method, measured pressure method, material balance method, etc. However, the individual application of these methods has certain limitations: the seismic layer velocity method can only macroscopically determine the vertical pressure distribution law and whether there is an abnormal pressure layer, and the seismic data are obtained in the early stage of exploration and are limited in timeliness; the well logging curve method is greatly affected by the recording of the well logging curves of adjacent wells and the configuration of drilling fluid; the measured pressure method is limited by the pressure measurement location and test conditions of adjacent wells; the material balance method can only qualitatively analyze the pressure changes and is limited by the sealing of the reservoir.

[0004] How to accurately predict formation pore pressure to ensure fast and safe drilling while protecting oil and gas layers, thereby improving the efficiency of a single well, is an aspect that requires special attention in the new situation of improving quality and efficiency. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for accurately predicting formation pore pressure in the entire well section of an developed old oil field, which overcomes the above problems or at least partially solves the above problems.

[0006] In order to solve the above technical problems, the present invention provides a method for accurately predicting the formation pore pressure of the entire well section of an developed old oil field, the method comprising the steps of:

[0007] Obtain formation pore pressure data for the entire well section of developed old oil fields;

[0008] Calculate the pressure coefficient value of the formation in the entire well section of the developed old oil field;

[0009] Obtaining pressure test data of target layers of all adjacent wells in the entire well section of the developed old oil field;

[0010] Screening the target layer pressure test data of all the adjacent wells;

[0011] Calibrate the pressure coefficient value according to the screening result;

[0012] The formation pore pressure value of the entire well section is obtained based on the calibration results.

[0013] Preferably, the step of obtaining the formation pore pressure data of the entire well section of the developed old oil field comprises the following steps:

[0014] Acquire block seismic velocity data of the entire well section of the developed old oil field;

[0015] Determine the formation pore pressure distribution law of the entire well section of the developed old oil field according to the seismic velocity data of the block;

[0016] The abnormal formation pore pressure distribution area of ​​the entire well section of the developed old oil field is determined based on the seismic velocity data of the block.

[0017] Preferably, the step of calculating the pressure coefficient value of the entire well section of the developed old oil field comprises the following steps:

[0018] Selecting adjacent wells in the entire well section of the developed old oil field that are adjacent to the designed well;

[0019] Acquiring logging curve data of the adjacent wells;

[0020] The pressure coefficient value of the formation in the entire well section of the developed old oil field is calculated according to the logging curve data.

[0021] Preferably, the step of selecting the adjacent wells in the entire well section of the developed old oil field that are adjacent to the designed well comprises the following steps:

[0022] Obtaining a designed well in the entire well section of the developed old oil field;

[0023] Acquire all adjacent wells in the entire well section of the developed old oil field that are located in the same oil reservoir as the target layer of the designed well;

[0024] Among all the adjacent wells, the one closest to the designed well is selected as the adjacent well.

[0025] Preferably, the step of obtaining the logging curve data of the adjacent wells comprises the following steps:

[0026] Acquiring the logging acoustic wave curve data of the adjacent well;

[0027] The well logging density curve data of the adjacent wells is obtained.

[0028] Preferably, the screening of all the target layer pressure test data of the adjacent wells comprises the steps of:

[0029] Obtaining reservoir injection and production data of the entire well section of the developed old oil field;

[0030] Dynamically analyzing the reservoir injection and production data and obtaining a first limit value of the pressure coefficient value;

[0031] Obtain drilling data of adjacent wells in the same reservoir as the target formation of the designed well;

[0032] Analyzing the drilling data and obtaining a second limit value of the pressure coefficient value;

[0033] The target layer pressure test data of the adjacent well is screened according to the first limit value and the second limit value.

[0034] Preferably, the step of dynamically analyzing the reservoir injection and production data and obtaining the first limit value of the pressure coefficient value comprises the following steps:

[0035] Acquiring all the injection and production data of the oil reservoir;

[0036] Calculating the cumulative injection-production ratio based on all the injection-production data of the oil reservoir;

[0037] Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well;

[0038] Determining whether the cumulative injection-production ratio is greater than or equal to a preset value;

[0039] If so, the original pressure coefficient is used as the lower limit of the pressure coefficient value;

[0040] If not, the original pressure coefficient is used as the upper limit of the pressure coefficient value.

[0041] Preferably, the step of analyzing the drilling data and obtaining the second limit value of the pressure coefficient value comprises the following steps:

[0042] Obtaining the drilling fluid density of the target formation of the adjacent well that has been drilled recently;

[0043] Calculating the pressure coefficient value interval of the recently completed well according to the drilling fluid density of the target layer;

[0044] Determining whether lost circulation occurs during the drilling process of the recently completed well;

[0045] If so, the left endpoint of the pressure coefficient value interval is used as the upper limit value of the pressure coefficient value;

[0046] If not, the right endpoint of the pressure coefficient value interval is used as the lower limit of the pressure coefficient value.

[0047] Preferably, the screening of the target layer pressure test data of the adjacent well according to the first limit value and the second limit value comprises the steps of:

[0048] Obtaining the first limit value and the second limit value;

[0049] Obtaining an intermediate value between the first limit value and the second limit value;

[0050] The intermediate value is used as the target layer pressure coefficient value of the designed well.

[0051] Preferably, the step of calibrating the pressure coefficient value according to the screening result comprises the following steps:

[0052] Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well;

[0053] Acquiring logging curve data of the adjacent wells;

[0054] Performing a first calibration on the logging curve data using the original pressure coefficient;

[0055] Acquire current production data of the entire well section of the developed old oil field;

[0056] Obtaining a target layer pressure coefficient value of the designed well;

[0057] The current production data is used to perform a second calibration on the target layer pressure coefficient value.

[0058] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages: the present application provides a method for accurately predicting the formation pore pressure of the entire well section of an already developed old oil field, which uses existing seismic velocity, measured pressure data and development dynamic data to comprehensively predict the pressure coefficient of the entire well section of the newly drilled well, thereby improving the pressure prediction accuracy of the new well, and on this basis, precise pressure-controlled drilling can be carried out, which not only ensures the safety of drilling and well control, but also lays a solid foundation for the high production and efficiency of new wells; various pressure prediction methods are comprehensively used to complement and verify each other, forming a systematic formation pore pressure prediction process, which effectively improves the prediction accuracy of formation pore pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 It is a flow chart of a method for accurately predicting formation pore pressure of the entire well section of an developed old oil field provided by an embodiment of the present invention;

[0061] Figure 2 It is a fault block well location deployment map in a method for accurately predicting formation pore pressure in the entire well section of an developed old oil field provided by an embodiment of the present invention;

[0062] Figure 3 It is a schematic diagram of the correction of the pressure coefficient of the entire well section of Well C in a method for accurately predicting the formation pore pressure of the entire well section of an developed old oil field provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The present invention will be described in detail below in conjunction with specific implementations and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific implementations and examples are used to illustrate the present invention, rather than to limit the present invention.

[0064] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0065] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0066] like Figure 1 In the embodiment of the present application, the present invention provides a method for accurately predicting the formation pore pressure of the entire well section of an developed old oil field, the method comprising the steps of:

[0067] S1: Obtain formation pore pressure data of the entire well section of the developed old oil field;

[0068] In the embodiment of the present application, the step of obtaining the formation pore pressure data of the entire well section of the developed old oil field includes:

[0069] Acquire block seismic velocity data of the entire well section of the developed old oil field;

[0070] Determine the formation pore pressure distribution law of the entire well section of the developed old oil field according to the seismic velocity data of the block;

[0071] The abnormal formation pore pressure distribution area of ​​the entire well section of the developed old oil field is determined based on the seismic velocity data of the block.

[0072] In an embodiment of the present application, block seismic velocity data of the formations in the entire well section of the developed old oil field, such as seismic intensity, etc., can be obtained by a seismic measuring instrument, and then the distribution law of formation pore pressure in the entire well section of the developed old oil field and the abnormal pore pressure distribution area of ​​the formations in the entire well section of the developed old oil field can be determined based on the obtained block seismic velocity data.

[0073] Specifically, the method for determining the distribution law of formation pore pressure in the entire well section of the developed old oil field based on the seismic velocity data of the block is that in normal pressure formations, as the burial depth of rocks increases, the pressure of overlying rock formations gradually increases and the formation porosity gradually decreases, so that the propagation velocity of seismic waves increases in direct proportion to the burial depth of rocks, and the propagation time decreases accordingly.

[0074] Method for determining the abnormal pore pressure distribution area of ​​the developed old oil field in the whole well section according to the seismic velocity data of the block: when the seismic wave reaches the high-pressure oil and gas layer, the propagation speed of the seismic wave in the fluid is lower than the propagation speed in the rock skeleton. In addition, due to the large porosity of the abnormally high-pressure formation, the propagation speed of the seismic wave decreases and the propagation time increases accordingly. Therefore, the seismic wave propagation time increases significantly with the increase of depth, which may be the display of the abnormally high-pressure layer.

[0075] In the embodiment of the present application, the benefit of obtaining the formation pore pressure data of the entire well section of the developed old oil field is to clarify whether there is abnormal pressure in the block and the approximate depth range of the abnormal pressure distribution, so as to grasp the overall characteristics of the block pressure from a macro perspective.

[0076] S2: Calculate the pressure coefficient value of the formation in the entire well section of the developed old oil field;

[0077] In the embodiment of the present application, the calculation of the pressure coefficient value of the entire well section of the developed old oil field includes the following steps:

[0078] Selecting adjacent wells in the entire well section of the developed old oil field that are adjacent to the designed well;

[0079] Acquiring logging curve data of the adjacent wells;

[0080] The pressure coefficient value of the formation in the entire well section of the developed old oil field is calculated according to the logging curve data.

[0081] In the embodiment of the present application, since the neighboring well adjacent to the designed well is close to the designed well, the pressure coefficient value of the neighboring well can be considered as the pressure coefficient value of the formation of the entire well section of the developed old oil field. The pressure coefficient value of the neighboring well (that is, the pressure coefficient value of the formation of the entire well section of the developed old oil field) can be calculated based on the well logging curve data of the neighboring well.

[0082] In the embodiment of the present application, the methods for calculating the pressure coefficient of the adjacent well based on the logging curve data of this adjacent well currently mainly include the Eaton method, the equivalent depth method and the effective stress method, and the most commonly used is the Eaton method; the logging curve method has high accuracy and low cost, and the pressure coefficient value of the entire well section of the developed old oil field is calculated by the logging curve data, and the pressure coefficient value is credible.

[0083] In the embodiment of the present application, the step of selecting the adjacent wells adjacent to the designed well in the entire well section of the developed old oil field comprises the following steps:

[0084] Obtaining a designed well in the entire well section of the developed old oil field;

[0085] Acquire all adjacent wells in the entire well section of the developed old oil field that are located in the same oil reservoir as the target layer of the designed well;

[0086] Among all the adjacent wells, the one closest to the designed well is selected as the adjacent well.

[0087] In the embodiment of the present application, in order to enhance the representativeness of the selection of the neighboring wells adjacent to the designed well, the neighboring well that is in the same reservoir as the target layer of the designed well and is closest to the designed well is deliberately selected as the representative of all the neighboring wells.

[0088] In the embodiment of the present application, the advantage of selecting an adjacent well adjacent to the designed well in the entire well section of the developed old oil field is that the adjacent well has a similar structural position and pressure coefficient to the designed well, and can better reflect the pressure conditions of the designed well.

[0089] In an embodiment of the present application, the step of obtaining the logging curve data of the adjacent wells includes the following steps:

[0090] Acquiring the logging acoustic wave curve data of the adjacent well;

[0091] The well logging density curve data of the adjacent wells is obtained.

[0092] In the embodiment of the present application, the logging curve data includes the logging acoustic wave curve data and the logging density curve data, and the logging acoustic wave curve data and the logging density curve data can be used to calculate the pressure coefficient value of the formation of the entire well section of the developed old oil field. Among them, the logging acoustic wave and density curve reflect the porosity and compaction degree of the overburden formation, and then reflect the pressure of the overburden formation.

[0093] S3: Obtaining pressure test data of target layers of all adjacent wells in the entire well section of the developed old oil field;

[0094] In the embodiment of the present application, the target layer pressure test data of the adjacent well includes the monitoring pressure during the drilling process and the measured pressure after drilling, and the methods for obtaining these test data are the DC index method and the actual measurement method.

[0095] S4: screening the target layer pressure test data of all the adjacent wells;

[0096] In an embodiment of the present application, the screening of all the target layer pressure test data of the adjacent wells includes the steps of:

[0097] Obtaining reservoir injection and production data of the entire well section of the developed old oil field;

[0098] Dynamically analyzing the reservoir injection and production data and obtaining a first limit value of the pressure coefficient value;

[0099] Obtain drilling data of adjacent wells in the same reservoir as the target formation of the designed well;

[0100] Analyzing the drilling data and obtaining a second limit value of the pressure coefficient value;

[0101] The target layer pressure test data of the adjacent well is screened according to the first limit value and the second limit value.

[0102] In an embodiment of the present application, the reservoir injection and production data of the entire well section of the developed old oil field are dynamically analyzed, and a first limit value can be obtained. At the same time, the drilling data of the adjacent wells in the same reservoir as the target layer of the designed well are analyzed, and a second limit value can be obtained. The first limit value and the second limit value can constitute an interval. The pressure test data of the target layer of the adjacent wells falling in this interval is the required data, and the data not in this interval is the unnecessary data.

[0103] In the embodiment of the present application, the benefit of screening the target layer pressure test data of all the adjacent wells is that the pressure prediction range of the well can be gradually and accurately designed by combining the original formation pressure, reservoir injection and production dynamics and drilling data of the adjacent wells.

[0104] In an embodiment of the present application, the step of dynamically analyzing the reservoir injection and production data and obtaining the first limit value of the pressure coefficient value comprises the following steps:

[0105] Acquiring all the injection and production data of the oil reservoir;

[0106] Calculating the cumulative injection-production ratio based on all the injection-production data of the oil reservoir;

[0107] Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well;

[0108] Determining whether the cumulative injection-production ratio is greater than or equal to a preset value;

[0109] If so, the original pressure coefficient is used as the lower limit of the pressure coefficient value;

[0110] If not, the original pressure coefficient is used as the upper limit of the pressure coefficient value.

[0111] In the embodiment of the present application, the cumulative injection-production ratio is calculated through reservoir injection-production data, and the cumulative injection-production ratio is compared with a preset value to determine the relationship between the original pressure coefficient and the pressure coefficient value.

[0112] Furthermore, the cumulative injection-production ratio is calculated based on the reservoir injection-production data, the cumulative injection volume and the cumulative production volume of the reservoir are calculated, and the cumulative injection volume is divided by the cumulative production volume to obtain the cumulative injection-production ratio. When the cumulative injection-production ratio is greater than 1, it is considered that energy is replenished to the formation and the formation pressure is greater than the original formation pressure. When the cumulative injection-production ratio is less than 1, it is considered that the formation energy is deficient and the formation pressure is less than the original formation pressure.

[0113] In the embodiment of the present application, by dynamically analyzing the reservoir injection and production data to obtain the first limit value of the pressure coefficient value, the difference between the current formation pressure coefficient of the designed well and the original pressure coefficient can be preliminarily determined.

[0114] In an embodiment of the present application, analyzing the drilling data and obtaining the second limit value of the pressure coefficient value includes the steps of:

[0115] Obtaining the drilling fluid density of the target formation of the adjacent well that has been drilled recently;

[0116] Calculating the pressure coefficient value interval of the recently completed well according to the drilling fluid density of the target layer;

[0117] Determining whether lost circulation occurs during the drilling process of the recently completed well;

[0118] If so, the left endpoint of the pressure coefficient value interval is used as the upper limit value of the pressure coefficient value;

[0119] If not, the right endpoint of the pressure coefficient value interval is used as the lower limit of the pressure coefficient value.

[0120] In an embodiment of the present application, the pressure coefficient value interval of the recently completed well is calculated by the drilling fluid density of the target layer, and the relationship between the pressure coefficient value interval and the pressure coefficient value is determined based on whether leakage occurs during the drilling process of the recently completed well.

[0121] Furthermore, the safety drilling fluid density added value for oil and water wells is 0.05-0.1g / cm3, and the safety drilling fluid density added value for gas wells is 0.07-0.15g / cm3. When the safety added value is subtracted from the drilling fluid density of the target layer, the pressure coefficient value range of the recently completed drilling is obtained.

[0122] In the embodiment of the present application, the drilling data is analyzed to obtain the second limit value of the pressure coefficient value, and a relatively safe pressure coefficient value range of the designed well is obtained.

[0123] In an embodiment of the present application, screening the target layer pressure test data of the adjacent well according to the first limit value and the second limit value includes the steps of:

[0124] Obtaining the first limit value and the second limit value;

[0125] Obtaining an intermediate value between the first limit value and the second limit value;

[0126] The intermediate value is used as the target layer pressure coefficient value of the designed well.

[0127] In the embodiment of the present application, after the first limit value and the second limit value are obtained, the middle value between the two can be used as the target layer pressure coefficient value of the designed well.

[0128] Furthermore, because the formation pressure coefficient for the target layer is a relatively fixed value rather than a range, the middle value between the first limit value and the second limit value is used as the target layer pressure coefficient value of the designed well. This pressure coefficient value is within a safe range and has a high accuracy.

[0129] The following describes step S4 and its sub-steps with reference to a specific embodiment.

[0130] like Figure 2 As shown in the figure, there are 3 old wells in a certain block, and all 3 old wells have pressure measurements. Among them, well B is the first well in the fault block to test oil and measure pressure, representing the original pressure coefficient. Wells A and D are recent pressure measurements, representing the current pressure coefficient. Due to the different pressure measurement times and pressure measurement wells, the pressure measurement results are different, which makes it difficult to predict the pressure of the newly designed well C. After dynamic analysis of the reservoir injection and production data, it is found that the cumulative injection-production ratio of the block is 1.03. At the same time, the cumulative injection-production ratio is greater than the preset value, so it is judged that the fault block pressure coefficient should be slightly higher than the original pressure coefficient ( Figure 2 The lower limit of the pressure coefficient is 1.02.

[0131] Further, it was found that the adjacent well D was recently drilled and the drilling fluid density of its target layer was 1.18g / cm 3 According to the safety added value, the corresponding pressure coefficient of the adjacent well D is estimated to be between 1.08 and 1.13. However, leakage occurred during the drilling process of the well, so the drilling fluid density of the well was set too high. It is estimated that the true pore pressure coefficient should be lower than 1.08, that is, the upper limit of the pressure coefficient is 1.08.

[0132] Through the above comprehensive analysis, it is believed that the pore pressure coefficient of the target layer of Well C should be between 1.02 and 1.08, and finally the middle number 1.05 is selected as the pressure coefficient value of the target layer of the well.

[0133] S5: Calibrate the pressure coefficient value according to the screening result;

[0134] In an embodiment of the present application, the calibrating the pressure coefficient value according to the screening result includes the steps of:

[0135] Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well;

[0136] Acquiring logging curve data of the adjacent wells;

[0137] Performing a first calibration on the logging curve data using the original pressure coefficient;

[0138] Acquire current production data of the entire well section of the developed old oil field;

[0139] Obtaining a target layer pressure coefficient value of the designed well;

[0140] The current production data is used to perform a second calibration on the target layer pressure coefficient value.

[0141] In the embodiments of the present application, Figure 3 As shown, the calibration is divided into two stages. The first calibration stage is: using the original pressure coefficient to perform a first calibration on the logging curve data; the second calibration stage is: using the current production data to perform a second calibration on the target layer pressure coefficient value.

[0142] In the embodiment of the present application, through two calibrations, the formation pressure coefficient value of the non-target layer of the designed well is made to be the original formation pressure coefficient value, and the target layer pressure coefficient value is the current formation pressure coefficient value, thereby ensuring the accuracy of the formation pressure coefficient value of the entire well section.

[0143] S6: Obtain the formation pore pressure value of the entire well section according to the calibration results.

[0144] In the embodiment of the present application, the formation pore pressure value of the entire well section can be obtained according to the two calibration results in step S5.

[0145] In the embodiment of the present application, the formation pressure coefficient value of the entire well section of the designed well is determined through the first calibration, and the current pressure coefficient value of the target layer is determined through the second calibration without changing the pressure coefficient of the non-target layer, thereby obtaining the current formation pressure coefficient value of the entire well section of the designed well.

[0146] The present application provides a method for accurately predicting the formation pore pressure of the entire well section of an already developed old oil field. The method uses existing seismic velocity, measured pressure data and development dynamic data to comprehensively predict the pressure coefficient of the entire well section of a newly drilled well, thereby improving the pressure prediction accuracy of the new well, and on this basis, precise pressure-controlled drilling can be carried out, which not only ensures the safety of drilling and well control, but also lays a solid foundation for the high production and efficiency of new wells. Various pressure prediction methods are comprehensively used to complement and verify each other, forming a systematic formation pore pressure prediction process, which effectively improves the prediction accuracy of formation pore pressure.

[0147] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. The various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

[0148] In short, the above is only a preferred embodiment of the technical solution of the present invention, and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for accurately predicting formation pore pressure in the entire well section of an developed old oil field, characterized in that: The method comprises the steps of: Obtain formation pore pressure data for the entire well section of developed old oil fields; Calculate the pressure coefficient value of the formation in the entire well section of the developed old oil field; Obtaining pressure test data of target layers of all adjacent wells in the entire well section of the developed old oil field; Screening the target layer pressure test data of all the adjacent wells; Calibrate the pressure coefficient value according to the screening result; Obtain the formation pore pressure value of the entire well section according to the calibration results; The screening of all the target layer pressure test data of the adjacent wells includes the following steps: Obtaining reservoir injection and production data of the entire well section of the developed old oil field; Dynamically analyzing the reservoir injection and production data and obtaining a first limit value of the pressure coefficient value; Obtain drilling data of adjacent wells in the same reservoir as the target formation of the designed well; Analyzing the drilling data and obtaining a second limit value of the pressure coefficient value; Filter the target layer pressure test data of the adjacent well according to the first limit value and the second limit value; The step of dynamically analyzing the reservoir injection and production data and obtaining the first limit value of the pressure coefficient value comprises the following steps: Acquiring all the injection and production data of the oil reservoir; Calculating the cumulative injection-production ratio based on all the injection-production data of the oil reservoir; Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well; Determining whether the cumulative injection-production ratio is greater than or equal to a preset value; If so, the original pressure coefficient is used as the lower limit of the pressure coefficient value; If not, the original pressure coefficient is used as the upper limit of the pressure coefficient value; The step of analyzing the drilling data and obtaining the second limit value of the pressure coefficient value comprises the following steps: Obtaining the drilling fluid density of the target formation of the adjacent well that has been drilled recently; Calculating the pressure coefficient value interval of the recently completed well according to the drilling fluid density of the target layer; Determining whether lost circulation occurs during the drilling process of the recently completed well; If so, the left endpoint of the pressure coefficient value interval is used as the upper limit value of the pressure coefficient value; If not, the right end point of the pressure coefficient value interval is used as the lower limit of the pressure coefficient value; The screening of the target layer pressure test data of the adjacent well according to the first limit value and the second limit value comprises the steps of: Obtaining the first limit value and the second limit value; Obtaining an intermediate value between the first limit value and the second limit value; The intermediate value is used as the target layer pressure coefficient value of the designed well.

2. The method for accurately predicting formation pore pressure in the entire well section of an already developed old oil field according to claim 1, characterized in that: The method of obtaining the formation pore pressure data of the entire well section of the developed old oil field comprises the following steps: Acquire block seismic velocity data of the entire well section of the developed old oil field; Determine the formation pore pressure distribution law of the entire well section of the developed old oil field according to the seismic velocity data of the block; The abnormal formation pore pressure distribution area of ​​the entire well section of the developed old oil field is determined based on the seismic velocity data of the block.

3. The method for accurately predicting formation pore pressure in the entire well section of an already developed old oil field according to claim 1, characterized in that: The calculation of the pressure coefficient value of the entire well section of the developed old oil field comprises the following steps: Selecting adjacent wells in the entire well section of the developed old oil field that are adjacent to the designed well; Acquiring logging curve data of the adjacent wells; The pressure coefficient value of the formation in the entire well section of the developed old oil field is calculated according to the logging curve data.

4. The method for accurately predicting formation pore pressure in the entire well section of an old oil field according to claim 3 is characterized in that: The step of selecting the adjacent wells in the entire well section of the developed old oil field that are adjacent to the designed well comprises the following steps: Obtaining a designed well in the entire well section of the developed old oil field; Acquire all adjacent wells in the entire well section of the developed old oil field that are located in the same oil reservoir as the target layer of the designed well; Among all the adjacent wells, the one closest to the designed well is selected as the adjacent well.

5. The method for accurately predicting formation pore pressure in the entire well section of an already developed old oil field according to claim 3, characterized in that: The step of obtaining the logging curve data of the adjacent wells comprises the following steps: Acquiring the logging acoustic wave curve data of the adjacent well; The well logging density curve data of the adjacent wells is obtained.

6. The method for accurately predicting formation pore pressure in the entire well section of an already developed old oil field according to claim 1, characterized in that: The calibrating of the pressure coefficient value according to the screening result comprises the steps of: Obtaining the original pressure coefficient in the target layer pressure test data of the adjacent well; Acquiring logging curve data of the adjacent wells; Performing a first calibration on the logging curve data using the original pressure coefficient; Acquire current production data of the entire well section of the developed old oil field; Obtaining a target layer pressure coefficient value of the designed well; The current production data is used to perform a second calibration on the target layer pressure coefficient value.

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