CN-121997520-A - Method and system for quantitatively representing fracturing effect of high-pressure gas well

CN121997520ACN 121997520 ACN121997520 ACN 121997520ACN-121997520-A

Abstract

The invention discloses a method and a system for quantitatively representing the fracturing effect of a high-pressure gas well, the reservoir is evaluated from multiple dimensions by acquiring three key flow data, pure matrix unimpeded flow, unimpeded flow before fracturing modification, and unimpeded flow after theoretical fracturing production extraction. And calculating the ratio of the natural capacity to the matrix capacity and the ratio of the target capacity to the matrix capacity, thereby obtaining the first equivalent fracturing transformation times. And the second equivalent fracturing transformation times are also based on the ratio of the target productivity to the matrix productivity. The first equivalent fracturing transformation times and the second equivalent fracturing transformation times are compared, so that quantitative characterization of the fracturing effect of the gas well can be realized. The quantitative evaluation mode can intuitively tell engineers and researchers whether the artificial fracturing modification effect is better, worse or equivalent relative to the modification effect of natural fractures of the reservoir. Meanwhile, the quantitative evaluation is also beneficial to comparison among different gas wells, and provides basis for selecting a more potential gas well for development.

Inventors

LIU JU
ZHONG BOWEN
REN DENGFENG
TENG QI
ZHANG YIGUO
PENG FEN
Lou Erbiao
LIU JIANGYU
LIU JIQUAN
LI YUZHEN

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (10)

1. A method for quantitatively characterizing the fracturing effect of a high-pressure gas well, comprising: obtaining pure matrix unimpeded flow, unimpeded flow before fracturing modification and unimpeded flow after theoretical fracturing extraction; Acquiring a ratio of natural productivity to matrix productivity according to the pure matrix unimpeded flow and the unimpeded flow before fracturing modification; Acquiring an equivalent wellbore radius of the natural fracture for wellbore reconstruction based on the ratio of the natural productivity to the matrix productivity, and acquiring first equivalent fracturing reconstruction times based on the equivalent wellbore radius of the natural fracture for wellbore reconstruction; Acquiring an equivalent shaft radius after fracturing modification based on the ratio of the target productivity to the substrate productivity, and acquiring second equivalent fracturing modification times based on the equivalent shaft radius after fracturing modification; And comparing the first equivalent fracturing transformation times with the second equivalent fracturing transformation times to realize quantitative characterization of the fracturing effect of the gas well.
2. The method for quantitatively characterizing the fracturing effect of a high-pressure gas well according to claim 1, wherein the method for acquiring pure matrix unimpeded flow, unimpeded flow before fracturing modification and unimpeded flow after theoretical fracturing extraction is specifically as follows: pure matrix unimpeded flow Unimpeded flow before fracturing modification Non-resistance flow after theoretical fracturing extraction Where k is the absolute permeability of the formation, h is the formation thickness, T sc is the temperature under standard conditions, Z sc is the gas deviation factor under standard conditions, P i is the original formation pressure, T is the gas reservoir temperature, P sc is the gas pressure under standard conditions, μ i is the gas viscosity under original gas reservoir conditions, Z i is the gas deviation factor under original gas reservoir conditions, r e is the gas reservoir drainage radius, r w is the wellbore radius, pi is the mathematical constant, ΔP is the difference between the gas reservoir boundary pressure P e and the bottom hole pressure P wf , r w "is the equivalent wellbore radius after theoretical fracturing modification, and r w ' is the equivalent wellbore radius of theoretical natural fractures to wellbore modification.
3. The method for quantitatively characterizing a fracturing effect of a high-pressure gas well according to claim 1, wherein the method is characterized in that the ratio of natural productivity to matrix productivity is obtained according to pure matrix unimpeded flow and unimpeded flow before fracturing modification, specifically comprises the following steps: Wherein, FOI nf is the ratio of natural productivity to matrix productivity, r e is the gas reservoir drainage radius, r w is the wellbore radius, and r w ' is the equivalent wellbore radius of the theoretical natural fracture to the wellbore modification.
4. The method for quantitatively characterizing a fracturing effect of a high-pressure gas well according to claim 1, wherein the method is characterized in that the ratio of the target capacity to the matrix capacity is obtained according to the pure matrix non-resistance flow and the theoretical fracturing production-improving non-resistance flow, specifically: Wherein FOI fac is the ratio of target capacity to matrix capacity, r e is the gas reservoir drainage radius, r w is the wellbore radius, and r w ' is the equivalent wellbore radius after theoretical fracturing modification.
5. The method for quantitatively characterizing fracturing effects of a high-pressure gas well according to claim 1, wherein the obtaining an equivalent wellbore radius of a natural fracture to wellbore modification based on a natural productivity to matrix productivity ratio is specifically as follows: Wherein r w1 ' is the equivalent wellbore radius of the natural fracture to wellbore reconstruction, n 1 is the first equivalent fracturing reconstruction times, x f is the productivity coefficient, and P is the formation pressure.
6. The method for quantitatively characterizing the fracturing effect of a high-pressure gas well according to claim 1, wherein the obtaining of the equivalent wellbore radius after fracturing modification based on the ratio of the target capacity to the matrix capacity is specifically as follows: Wherein r w1 ' is the equivalent wellbore radius after fracturing modification, n 2 is the first equivalent fracturing modification times, x f is the productivity coefficient, and P is the formation pressure.
7. A method for quantitatively characterizing the fracturing effect of a high-pressure gas well, comprising: The first data acquisition module is used for acquiring pure matrix unimpeded flow, unimpeded flow before fracturing modification and unimpeded flow after theoretical fracturing extraction; The system comprises a first data acquisition module, a second data acquisition module, a first data processing module and a second data processing module, wherein the first data acquisition module is used for acquiring the ratio of natural productivity to matrix productivity according to pure matrix unimpeded flow and unimpeded flow before fracturing modification; The first transformation frequency acquisition module is used for acquiring an equivalent shaft radius of the natural fracture on shaft transformation based on the ratio of the natural productivity to the matrix productivity and acquiring first equivalent fracturing transformation frequency based on the equivalent shaft radius of the natural fracture on shaft transformation; The second transformation frequency acquisition module is used for acquiring the equivalent shaft radius after fracturing transformation based on the ratio of the target capacity to the matrix capacity and acquiring the second equivalent fracturing transformation frequency based on the equivalent shaft radius after fracturing transformation; The comparison module is used for comparing the first equivalent fracturing transformation times and the second equivalent fracturing transformation times, and realizing quantitative characterization of the fracturing effect of the gas well.
8. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the computer program, realizes the steps of the method for quantitatively characterizing the fracturing effect of a high pressure gas well as claimed in any one of claims 1-6.
9. A computer readable storage medium storing a computer program, wherein the computer program when executed by a processor performs the steps of the method of quantitatively characterizing a high pressure gas well fracturing effect according to any one of claims 1 to 6.
10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, realizes the steps of the method of quantitatively characterizing the fracturing effect of a high pressure gas well as claimed in any one of claims 1 to 6.

Description

Method and system for quantitatively representing fracturing effect of high-pressure gas well Technical Field The invention belongs to the technical field of fracturing transformation, and relates to a method and a system for quantitatively representing a fracturing effect of a high-pressure gas well. Background The fracturing improves the yield of the gas well by reducing the seepage resistance of the stratum near the bottom of the well, the diversion capacity of the formed sand filling cracks is much larger than the original stratum coefficient, and the communication capacity of the stratum to the well shaft is greatly improved. The method changes the flow form, changes radial flow into bilinear flow, increases the seepage cross section, reduces seepage resistance, can communicate with an independent lens body or a natural fracture system, and adds a new oil gas source. The cracks penetrate the contaminated plugging zone of the formation near the bottom of the well, unblocking, and thus can significantly increase the production. The fracturing effect evaluation method and device provided by the prior art are used for determining fracturing implementation effect evaluation indexes according to fracturing design data and on-site implementation data, and evaluating fracturing effects according to the fracturing yield increase effect evaluation indexes and the fracturing implementation effect evaluation indexes, so that the accuracy of fracturing effect evaluation is improved. A method and a device for evaluating the hydraulic fracturing effect of a stratum are provided, array acoustic logging is carried out in a depth interval, dipole acoustic logging data in different directions are constructed, filtering treatment and normalization treatment are carried out on the dipole acoustic logging data in different directions, the energy envelopes of scattered wave before and after fracturing are calculated, and the effect of a well Zhou Yalie is evaluated by utilizing the difference of the transverse wave velocity of the dipole acoustic logging and the difference of the scattered wave energy before and after fracturing. A method for predicting the output of unconventional oil-gas well and evaluating the fracturing effect features that a fracturing flowback history analysis module is used to utilize the flowback data after fracturing, which is frequently ignored in site, to evaluate the initial effective pore volume and volume loss rate of crack. The existing evaluation technology is qualitative or semi-quantitative, has little meaning on process selection guidance, and cannot quantitatively represent the fracturing effect of the high-pressure gas well. Therefore, the method for quantitatively characterizing the fracturing effect of the high-pressure gas well is studied and explored in depth, and has important research and application values. Disclosure of Invention The invention aims to solve the problem that the fracturing effect of a high-pressure gas well cannot be quantitatively represented in the prior art, and provides a method and a system for quantitatively representing the fracturing effect of the high-pressure gas well. In order to achieve the purpose, the invention is realized by adopting the following technical scheme: the invention provides a method for quantitatively representing the fracturing effect of a high-pressure gas well, which comprises the following steps: obtaining pure matrix unimpeded flow, unimpeded flow before fracturing modification and unimpeded flow after theoretical fracturing extraction; Acquiring a ratio of natural productivity to matrix productivity according to the pure matrix unimpeded flow and the unimpeded flow before fracturing modification; Acquiring an equivalent wellbore radius of the natural fracture for wellbore reconstruction based on the ratio of the natural productivity to the matrix productivity, and acquiring first equivalent fracturing reconstruction times based on the equivalent wellbore radius of the natural fracture for wellbore reconstruction; Acquiring an equivalent shaft radius after fracturing modification based on the ratio of the target productivity to the substrate productivity, and acquiring second equivalent fracturing modification times based on the equivalent shaft radius after fracturing modification; And comparing the first equivalent fracturing transformation times with the second equivalent fracturing transformation times to realize quantitative characterization of the fracturing effect of the gas well. Preferably, the method for obtaining the pure matrix unimpeded flow, the unimpeded flow before fracturing modification and the unimpeded flow after theoretical fracturing extraction specifically comprises the following steps: pure matrix unimpeded flow Unimpeded flow before fracturing modification Non-resistance flow after theoretical fracturing extraction Where k is the absolute permeability of the formation, h is the formation thickness, T sc is