CN-121993194-A - Identification method, device, equipment and storage medium for low-mineralization stratum water

CN121993194ACN 121993194 ACN121993194 ACN 121993194ACN-121993194-A

Abstract

The invention belongs to the technical field of oil and gas field development, and discloses a method for identifying low-mineralization stratum water, which comprises the steps of obtaining data corresponding to a test oil well through drilling data, and then comparing step by step according to the obtained data to judge whether stratum water is discharged. The method is suitable for identifying the low-mineralization stratum water, judges whether the stratum is discharged or not in real time by draining the test oil well, provides an important basis for identifying the low-mineralization stratum water, and makes up the defect of a stratum water judging method.

Inventors

GAN HUIJUAN
YANG CHUNHUA
LI JIN
ZHENG LIJUN
SUN YUHAN
TANG QIWEI
ZHOU QIANYU
ZHANG LING
ZHANG YUQING
LI RUOHUA
ZHANG XIAOMENG
JIANG WANXUE
WANG LU
TAN ZHEN
GONG HANG
SHI XIAOMENG
WU LIQIANG
LIANG CHI
CHEN XI
LIU CHAOWU
BAI TIANZENG

Assignees

中国石油集团渤海钻探工程有限公司
中国石油天然气集团有限公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (5)

1. The identification method of the low-mineralization stratum water is characterized by comprising the following steps of: S1, obtaining the chloride ion concentration a of reservoir drilling fluid corresponding to different test wells through drilling data; before each test oil well is drained, calculating the internal pressure well liquid volume b in the shaft before the drain of each test oil well, and performing assay analysis to obtain the chloride ion concentration c of the original power liquid; in the process of draining each test oil well, recording the daily water yield d and the accumulated water drainage e of the drain water of each test oil well and the volume f of the supplementary power fluid in real time, testing and analyzing to obtain the chloride ion concentration g of the drain water, and comparing whether the accumulated water drainage e is larger than the sum of the volume b of the internal pressure well fluid in the shaft before draining and the volume f of the supplementary power fluid; S2, in the process of draining each test oil well, when the accumulated drainage quantity e of the test oil well is greater than the sum of the internal pressure well fluid volume B of the shaft and the complementary power fluid volume f before draining, judging formation water of the test oil well, taking latest drainage water in the process of draining, performing full analysis and test to obtain an ion concentration data table A, calculating the total mineralization value and determining the water type; When the accumulated water discharge e of the test oil well is less than or equal to the sum of the internal pressure well liquid volume b of the shaft before liquid discharge and the supplementary power liquid volume f, if the discharged water chloride ion concentration g is less than or equal to the original power liquid chloride ion concentration c, continuing liquid discharge, and observing the subsequent accumulated water discharge e and the discharged water chloride ion concentration g until the discharged water chloride ion concentration g is greater than the original power liquid chloride ion concentration c; S3, if the discharged water chloride ion concentration g is greater than the original power fluid chloride ion concentration c, comparing the discharged water chloride ion concentration g with the reservoir drilling fluid chloride ion concentration a, and performing step S4 or step S5; S4, when the chloride ion concentration g of the discharged water is less than or equal to the chloride ion concentration a of the reservoir drilling fluid, observing the change of the daily water yield d at the moment, if the daily water yield d is gradually reduced, judging that the discharged water at the moment is drilling mud filtrate and the stratum does not discharge water, and if the daily water yield d is gradually increased or kept unchanged, performing a step S6; S5, when the chloride ion concentration g of the discharged water is greater than the chloride ion concentration a of the reservoir drilling fluid, performing a step S6; S6, taking the latest discharged water in the liquid discharge process, and performing full analysis and test to obtain an ion concentration data table A 1 ; S7, carrying out concentration comparison analysis on the ion concentration data table A 1 and the same ions in the database B obtained by the oil test well which is judged to be the formation water outlet in the step S2, if the difference of the ion concentrations is less than or equal to 30%, drawing an ion equivalent plate C 1 corresponding to the ion concentration data table A 1 , fitting the ion equivalent plate C with the regional formation water ion equivalent plate C, if the fitting form of the plate curves is consistent, judging the formation water outlet, inputting the ion concentration data table A 1 into the database B, adding the corresponding ion equivalent plate C 1 into the regional formation water ion equivalent plate C, and if the fitting form of the plate curves is inconsistent, judging that the formation water outlet is not generated.
2. The method of claim 1, wherein the ion concentration data table a includes sodium and potassium ion concentrations, magnesium ion concentrations, calcium ion concentrations, chloride ion concentrations, sulfate ion concentrations, bicarbonate ion concentrations, carbonate ion concentrations, iodide ion concentrations, and boron ion concentrations.
3. A low mineralization formation water identification device, comprising: the system comprises a data acquisition module, a data analysis module, a control module and a control module, wherein the data acquisition module is used for acquiring the chloride ion concentration a of reservoir drilling fluid corresponding to different test wells through drilling data, calculating the volume b of the internal pressure of a well bore before the fluid drainage of each test well, and performing assay analysis to acquire the chloride ion concentration c of original power fluid; The regional stratum water ion equivalent chart acquisition module is used for judging stratum water of each test oil well when the accumulated water discharge e of the test oil well is equal to the sum of the internal pressure well liquid volume B of the shaft before liquid discharge and the complementary power liquid volume f in the process of liquid discharge of each test oil well, taking latest discharged water in the process of liquid discharge, performing full analysis and test to obtain an ion concentration data table A, simultaneously calculating the total mineralization value and determining water type; The first judging module is used for continuously draining water when the accumulated drainage quantity e of the test oil well is less than or equal to the sum of the internal pressure well liquid volume b of the shaft before draining water and the supplementary power liquid volume f, and if the chloride ion concentration g of the drained water is less than or equal to the chloride ion concentration c of the original power liquid, observing the subsequent accumulated drainage quantity e and the chloride ion concentration g of the drained water until the chloride ion concentration g of the drained water is greater than the chloride ion concentration c of the original power liquid; The second judging module is used for comparing the discharged water chloride ion concentration g with the reservoir drilling fluid chloride ion concentration a if the discharged water chloride ion concentration g is greater than the original power fluid chloride ion concentration c; The third judging module is used for observing the change of the daily water yield d when the chloride ion concentration g of the discharged water is less than or equal to the chloride ion concentration a of the reservoir drilling fluid, judging that the discharged water is drilling mud filtrate and stratum does not discharge water when the daily water yield d is gradually reduced, and carrying out an ion concentration data table acquisition module when the daily water yield d is gradually increased or kept unchanged; The fourth judging module is used for performing an ion concentration data table acquisition module when the discharged water chloride ion concentration g is greater than the reservoir drilling fluid chloride ion concentration a; the ion concentration data table acquisition module is used for taking the latest discharged water in the liquid discharge process and performing full analysis and assay to obtain an ion concentration data table A 1 ; And a fifth judging module, configured to perform concentration comparison analysis on the ion concentration data table a 1 and the same ions in the database B obtained from the test oil well that has been judged to be the formation water outlet, if the difference between the ion concentrations is less than or equal to 30%, then draw an ion equivalent plate C 1 corresponding to the ion concentration data table a 1 , fit the ion equivalent plate C with the regional formation water ion equivalent plate C, if the plate curve fitting form is consistent, judge the formation water outlet, input the ion concentration data table a 1 into the database B, and add the corresponding ion equivalent plate C 1 into the regional formation water ion equivalent plate C, and if the plate curve fitting form is inconsistent, judge that the formation water outlet is not generated.
4. A computer device, characterized in that it comprises a processor and a memory for storing at least one section of a computer program, which is loaded by the processor and which performs the method for identifying low salinity formation water according to any one of claims 1-2.
5. A storage medium, characterized in that the storage medium is used for storing at least one section of computer program for executing the method for identifying low mineralization formation water according to any one of claims 1-2.

Description

Identification method, device, equipment and storage medium for low-mineralization stratum water Technical Field The invention belongs to the technical field of oil and gas field development, and relates to a method, a device, equipment and a storage medium for identifying low-mineralization stratum water. Background The oil test is composed of a series of single technologies such as shaft treatment, well killing, perforation, stratum testing, liquid discharge, production and ground metering, measure transformation, data analysis and processing, and the like, and the steps aim to directly test underground oil and gas layers through special tools, equipment and methods and acquire related data such as productivity, pressure, liquid property, temperature and the like, and are important means for finally determining whether oil and gas exist in a production layer or a structure, judging whether the oil and gas exist in the production layer or the structure, and directly knowing the underground condition, so that the data acquired by the oil test are required to be accurate and reliable to provide scientific basis for oil reservoir evaluation and development. The accurate judgment of the liquid property serves as an important link, and an important basis is provided for the establishment of exploration and development schemes. Common oil field stratum water has higher mineralization degree and is easy to identify in the process of oil testing and drainage. However, the identification of low mineralization formation water is affected by mud filtrate, well washing water, well killing liquid, power liquid, fracturing liquid, acid liquid and the like, so that the common oil testing and draining process cannot meet the aim of oil testing, and a draining process is required to be optimized for production, such as the formation water with a concave retaining recess Qingyuan in a Ji, but the defect of the draining process can cause oil emulsification and influence the judgment of formation water discharge because the drainage requires the power liquid to circulate to drive the formation liquid to drain out of the ground, so that the identification of low mineralization formation water is difficult. Therefore, the method for accurately judging the low-mineralization stratum water is very necessary, can effectively improve the accuracy of liquid determination, and has important practical significance. Disclosure of Invention The invention aims to provide a method for identifying low-mineralization stratum water, which is characterized in that in the process of draining a test oil well, whether the stratum is water-out is judged by comparing the accumulated drainage e with the sum of the internal pressure well liquid volume b of a shaft before draining and the volume f of a supplementary power liquid, and whether the stratum is water-out is further judged by comparing an regional stratum water ion equivalent plate C and an ion equivalent plate C 1, so that the problem of identifying the stratum water is solved, and the accuracy of obtaining the liquid is effectively improved; Another object of the present invention is to provide a device, apparatus and storage medium for identifying formation water of low mineralization. The technical scheme adopted by the invention for realizing the purposes is as follows: a method for identifying low mineralization formation water, comprising the following steps: S1, obtaining the chloride ion concentration a of reservoir drilling fluid corresponding to different test wells through drilling data; before each test oil well is drained, calculating the internal pressure well liquid volume b in the shaft before the drain of each test oil well, and performing assay analysis to obtain the chloride ion concentration c of the original power liquid; in the process of draining each test oil well, recording the daily water yield d and the accumulated water drainage e of the drain water of each test oil well and the volume f of the supplementary power fluid in real time, testing and analyzing to obtain the chloride ion concentration g of the drain water, and comparing whether the accumulated water drainage e is larger than the sum of the volume b of the internal pressure well fluid in the shaft before draining and the volume f of the supplementary power fluid; S2, in the process of draining each test oil well, when the accumulated drainage quantity e of the test oil well is greater than the sum of the internal pressure well fluid volume B of the shaft and the complementary power fluid volume f before draining, judging formation water of the test oil well, taking latest drainage water in the process of draining, performing full analysis and test to obtain an ion concentration data table A, calculating the total mineralization value and determining the water type; When the accumulated water discharge e of the test oil well is less than or equal to the sum of the internal pressure well liquid volume b