CN112257349A - Method for judging whether compact sandstone movable water-gas reservoir gas well has development value - Google Patents

Method for judging whether compact sandstone movable water-gas reservoir gas well has development value Download PDF

Info

Publication number
CN112257349A
CN112257349A CN202011031046.1A CN202011031046A CN112257349A CN 112257349 A CN112257349 A CN 112257349A CN 202011031046 A CN202011031046 A CN 202011031046A CN 112257349 A CN112257349 A CN 112257349A
Authority
CN
China
Prior art keywords
gas
gas well
formation
movable water
reservoir
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
CN202011031046.1A
Other languages
Chinese (zh)
Other versions
CN112257349B (en
Inventor
刘莉莉
兰义飞
杨辉
江乾锋
刘会会
陈新
安红燕
王威
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.)
Petrochina Co Ltd
Original Assignee
Petrochina Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Petrochina Co Ltd filed Critical Petrochina Co Ltd
Priority to CN202011031046.1A priority Critical patent/CN112257349B/en
Publication of CN112257349A publication Critical patent/CN112257349A/en
Application granted granted Critical
Publication of CN112257349B publication Critical patent/CN112257349B/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
    • G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
    • 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
    • G06F2113/00—Details relating to the application field
    • G06F2113/08—Fluids
    • 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)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Business, Economics & Management (AREA)
  • Tourism & Hospitality (AREA)
  • Agronomy & Crop Science (AREA)
  • Health & Medical Sciences (AREA)
  • Economics (AREA)
  • General Health & Medical Sciences (AREA)
  • Human Resources & Organizations (AREA)
  • Marketing (AREA)
  • Primary Health Care (AREA)
  • Strategic Management (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Marine Sciences & Fisheries (AREA)
  • General Business, Economics & Management (AREA)
  • Animal Husbandry (AREA)
  • Mining & Mineral Resources (AREA)
  • Algebra (AREA)
  • Computing Systems (AREA)
  • Fluid Mechanics (AREA)
  • Mathematical Analysis (AREA)
  • Mathematical Optimization (AREA)
  • Mathematical Physics (AREA)
  • Pure & Applied Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Evolutionary Computation (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)

Abstract

The invention provides a method for judging whether a tight sandstone movable water gas reservoir gas well has development value or not, which considers the effective gas phase permeability k of movable water in the reservoirgComprehensive viscosity of formation fluid
Figure DDA0002703686560000011
And a flow boundary reAnd three influencing factors are used for establishing a tight sandstone water-bearing gas reservoir gas well productivity calculation formula, so that the gas well productivity can be accurately calculated. The invention establishes an empirical formula of effective permeability when stratum movable water exists in the test rock core and block by combining indoor test and practical application, and enlarges the water content of the compact sandstoneThe reutilization of the core experiment data in the gas reservoir scientifically and reasonably evaluates the gas well productivity of the gas reservoir, and influence factors and change rules thereof, can quickly evaluate the influence degree of the formation movable water on the productivity under different reservoir conditions, and is beneficial to reasonable production allocation and formulation of a reasonable development technical policy of the compact sandstone water-containing gas reservoir.

Description

Method for judging whether compact sandstone movable water-gas reservoir gas well has development value
Technical Field
The invention belongs to the technical field of gas reservoir engineering, and particularly relates to a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value.
Background
The tight sandstone water-containing gas reservoir occupies a great position in natural gas reserves, the large-scale benefit development of the water-containing gas reservoir faces a great technical challenge, and the accurate calculation of the productivity of the tight sandstone water-containing gas reservoir gas well has very important significance for long-term stable production of the water-producing gas well and fine management of the gas well. The related technologies of the existing method for evaluating the productivity of the gas well of the tight sandstone water-containing gas reservoir comprise tight sandstone water-containing gas reservoir seepage mechanism experiments, theoretical model researches, a tight sandstone gas reservoir low-speed nonlinear abortion energy formula and the like.
The conventional evaluation method has a larger problem, the main problem of the seepage mechanism experimental technology is that the visualization experiment of a real core slice reveals the gas-water distribution change rule in the gas-water displacement process, although the permeability of a sample is also measured, the two-dimensional rock slice cannot obtain the influence rule of different water saturation on the effective permeability, in addition, the wettability of a glass partition plate in a visualization model is different from that of the actual stratum rock, and the influence of the wettability of a pore passage of a compact reservoir on the seepage rule is very obvious; the CT scanning digital core technology is expensive in cost, is limited by scanning precision and resolution, and has great limitation on the pore structure simulation function of the compact reservoir rock; a power function type empirical formula of the starting pressure gradient, the absolute permeability and the water saturation of the rock core is established according to the high-precision rock core test, but the power function type empirical formula is not consistent with an internationally recognized exponential function that the starting pressure gradient is fluidity. For the problems existing in the productivity formula of the low-speed nonlinear seepage theory, most researches are only limited to adding a starting pressure gradient in a mathematical model, stress sensitivity and slip effect are considered through a coefficient term, but the influence rule of movable water on the formation flow capacity is not considered from the angle of influencing the nonlinear seepage characteristic; the influence of the boundary layer in the microchannel on the seepage rule can be considered in part of more complex theoretical models, and the influence of stress sensitivity, a slip effect, a starting pressure gradient, movable water saturation and the like on the seepage rule can be considered, but the parameters required by the models are often difficult to obtain completely and the solution is difficult.
The existence of movable water aggravates the nonlinear seepage characteristic of tight sandstone gas reservoir rock, obviously reduces the flowing capacity of the rock, and has great influence on the gas well productivity, the stable production capacity, the gas sand recovery ratio and the like. The method has the advantages that the influence degree of the productivity of the gas well of the water-tight sandstone gas reservoir and the stratum yielding water on the productivity of the gas well is evaluated scientifically and reasonably, and the optimization of the gas well production allocation and field development strategies is facilitated.
Disclosure of Invention
The invention aims to provide a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value or not, and the technical problems in the prior art are solved.
Therefore, the invention provides a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value, which comprises the following steps:
step 1) obtaining the gas well productivity qscAnd the movable water saturation degree SwmThe relational expression of (1);
step 2) let the movable water saturation SwmIs 0, according to gas well productivity qscAnd the movable water saturation degree SwmTo obtain the gas well productivity qsc0；
Step 3) calculating the saturation S of each movable waterwmCorresponding gas well productivity qscBy qsc/qsc0Obtaining the productivity retention rate;
step 4) obtaining movable water saturation SwmA graph relating to productivity retention;
step 5) when the movable water saturation SwmAnd when the productivity retention rate is more than 15% and less than 0.2, judging that the gas reservoir gas well has no development value.
Step 1) the gas well productivity qscAnd the movable water saturation degree SwmIs given by the gas phase effective permeability k of the mobile water in the reservoirgComprehensive viscosity of formation fluid
Figure BDA0002703686540000021
And a flow boundary reThree influencing factors are obtained.
Step 1) obtaining the gas well productivity qscAnd the movable water saturation degree SwmThe specific process of the relation of (1) is as follows:
(1) obtaining the gas phase effective permeability k of the rock according to the gas-water flow test data of the rock coregAnd the movable water saturation degree SwmAbsolute permeability k∞The relational expression of (1);
(2) according to the viscosity of natural gas under the average pressure of stratum
Figure BDA0002703686540000022
Formation water viscosity muwAnd the movable water saturation degree SwmObtaining the comprehensive viscosity of the formation fluid under the formation condition
Figure BDA0002703686540000023
(3) Establishing a flow boundary reFlow pressure p along with bottom holewThe variation relation of (1);
(4) according to the gas phase effective permeability k of the rockgComprehensive viscosity of formation fluid
Figure BDA0002703686540000024
And a flow boundary reEstablishing a compact sandstone water-bearing gas reservoir gas well productivity calculation formula to obtain the gas well productivity qscWith mobile water saturationDegree SwmThe relational expression (c) of (c).
Step (1) combines the gas phase effective permeability k of the rock under different movable water saturation conditions of the rock coregRegression establishes different absolute permeabilities k∞And movable water saturation SwmThe following empirical formula for effective permeability:
kg＝k∞·krg(Swm)
in the formula, k∞Is the rock absolute permeability, mD; k is a radical ofrg(Swm) As movable water saturation SwmAnd permeability retention rate krgThe relational expression (c) of (c).
Step (2) is carried out by measuring the viscosity of the natural gas under the average pressure of the stratum
Figure BDA0002703686540000031
Viscosity mu with formation waterwDegree of movable water saturation SwmWeighting to obtain the comprehensive viscosity of the formation fluid
Figure BDA0002703686540000032
Figure BDA0002703686540000033
In the formula (I), the compound is shown in the specification,
Figure BDA0002703686540000034
viscosity of natural gas, cP, at the average pressure of the formation; mu.swFormation water viscosity, cP;
Figure BDA0002703686540000035
is the formation fluid integrated viscosity, cP; swmIs the formation mobile water saturation.
Step (3) is to establish a flow boundary r based on the radial flow stratum pressure distribution and the starting pressure gradient, the gas well production pressure difference, the seepage characteristic and the fluid parametereFlow pressure p along with bottom holewThe variation relation of (1);
Figure BDA0002703686540000036
in the formula, pwIs bottom hole flowing pressure, MPa; p is a radical ofiIs the formation static pressure, MPa; k is a radical ofgIs the gas phase effective permeability, mD, of the rock;
Figure BDA0002703686540000037
is the formation fluid integrated viscosity, cP.
Step (3) gas well productivity qscAnd the movable water saturation degree SwmThe relationship of (A) is as follows:
Figure BDA0002703686540000038
in the formula, qscFor gas well production, m3/d；kgIs the gas phase effective permeability, mD, of the reservoir rock; h is the effective thickness of the reservoir, m; p is a radical ofiIs the formation static pressure, MPa; p is a radical ofwIs bottom hole flowing pressure, MPa; t is the formation temperature, K;
Figure BDA0002703686540000039
is the formation fluid integrated viscosity, cP;
Figure BDA00027036865400000310
is the mean formation gas eccentricity factor; r iseIs the gas well flow boundary, m; r iswIs the gas well borehole radius, m; s is the epidermal coefficient; swmIs the formation mobile water saturation.
Local formation pressure gradient griWhen the starting pressure gradient lambda is not exceeded, the corresponding distance rbIs the flow boundary r corresponding to the bottom hole pressuree：
Figure BDA0002703686540000041
In the formula, rbIs the radial distance, m, of the gas well flow boundary; griIs the formation pressure gradient, m; lambda is startDynamic pressure gradient, m.
The invention has the beneficial effects that:
the method for judging whether the tight sandstone movable water-gas reservoir gas well has development value or not is characterized by considering the effective gas-phase permeability k of the movable water in the reservoirgComprehensive viscosity of formation fluid
Figure BDA0002703686540000042
And a flow boundary reAnd three influencing factors are used for establishing a tight sandstone water-bearing gas reservoir gas well productivity calculation formula, so that the gas well productivity can be accurately calculated.
According to the method, through the combination of indoor tests and practical application, an effective permeability empirical formula is established when the test rock core and the block have stratum movable water, the reutilization of the experimental data of the rock core in the tight sandstone water-containing gas reservoir is expanded, the gas well productivity of the gas reservoir and the influence factors and the change rule thereof are evaluated scientifically and reasonably, and the reasonable production allocation and the reasonable development technical policy of the tight sandstone water-containing gas reservoir are facilitated.
The method can quickly evaluate the influence degree of the stratum movable water on the productivity under different reservoir conditions.
The following will be described in further detail with reference to the accompanying drawings.
Drawings
FIG. 1 is a graph of movable water saturation versus permeability retention for cores 51 wells 2-1/125 according to an example of the present invention;
FIG. 2 is a graph of movable water saturation versus permeability retention for cores from x73 wells 3-17/44 in accordance with an embodiment of the present invention;
FIG. 3 is a graph of movable water saturation versus permeability retention for cores from x29 wells 2-5/133 in accordance with an embodiment of the present invention;
FIG. 4 is a graph of movable water saturation versus permeability retention for cores from x124 wells 5-13/47 in accordance with an embodiment of the present invention;
FIG. 5 is a graph of the effect of mobile water saturation on capacity retention.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Example 1:
the embodiment provides a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value, which comprises the following steps:
step 1) obtaining the gas well productivity qscAnd the movable water saturation degree SwmThe relational expression of (1);
step 2) let the movable water saturation SwmIs 0, according to gas well productivity qscAnd the movable water saturation degree SwmTo obtain the gas well productivity qsc0；
Step 3) calculating the saturation S of each movable waterwmCorresponding gas well productivity qscBy qsc/qsc0Obtaining the productivity retention rate;
step 4) obtaining movable water saturation SwmA graph relating to productivity retention;
step 5) when the movable water saturation SwmAnd when the productivity retention rate is more than 15% and less than 0.2, judging that the gas reservoir gas well has no development value.
The method helps to reasonably allocate the production and establish a reasonable development technical policy of the compact sandstone water-containing gas reservoir by researching the influence of the dynamic water saturation on the productivity conservation rate.
Example 2:
on the basis of the embodiment 1, the embodiment provides a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value, and the gas well productivity q in the step 1) isscAnd the movable water saturation degree SwmIs given by the gas phase effective permeability k of the mobile water in the reservoirgComprehensive viscosity of formation fluid
Figure BDA0002703686540000051
And a flow boundary reThree influencing factors are obtained.
This example establishes a gas phase effective permeability k that takes into account mobile water within the reservoirgComprehensive viscosity of formation fluid
Figure BDA0002703686540000052
And a flow boundary reThe productivity calculation formula of the tight sandstone water-bearing gas reservoir gas well under the three influence factors effectively solves the problems that the existing gas well productivity evaluation method is complex and inaccurate in calculation, and can achieve the purpose of quickly calculating the productivity of the tight sandstone water-bearing gas reservoir gas well.
Example 3:
on the basis of the embodiment 1 or 2, the embodiment provides a method for judging whether the tight sandstone movable water-gas reservoir gas well has development value, and the step 1) obtains the gas well productivity qscAnd the movable water saturation degree SwmThe specific process of the relation of (1) is as follows:
(1) obtaining the gas phase effective permeability k of the rock according to the gas-water flow test data of the rock coregAnd the movable water saturation degree SwmAbsolute permeability k∞The relational expression of (1);
(2) according to the viscosity of natural gas under the average pressure of stratum
Figure BDA0002703686540000061
Formation water viscosity muwAnd the movable water saturation degree SwmObtaining the formation conditionsIntegrated viscosity of formation fluid
Figure BDA0002703686540000062
(3) Establishing a flow boundary reFlow pressure p along with bottom holewThe variation relation of (1);
(4) according to the gas phase effective permeability k of the rockgComprehensive viscosity of formation fluid
Figure BDA0002703686540000063
And a flow boundary reEstablishing a compact sandstone water-bearing gas reservoir gas well productivity calculation formula to obtain the gas well productivity qscAnd the movable water saturation degree SwmThe relational expression (c) of (c).
The method combines the indoor test with the practical application, expands the reutilization of the indoor core test data of the tight sandstone water-containing gas reservoir, establishes the effective permeability empirical formula when the test core and the block have the stratum movable water, and scientifically and reasonably evaluates the gas well productivity of the gas reservoir, the influence factors and the change rule thereof. The gas well productivity equation considers nonlinear influence factors such as movable water, a flow boundary and the like, and the calculation result is more accurate.
Example 4:
on the basis of embodiment 3, the embodiment provides a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value, and the step (1) is to combine the gas-phase effective permeability k of the rock under the conditions of different movable water saturations of the rock coregRegression establishes different absolute permeabilities k∞And movable water saturation SwmThe following empirical formula for effective permeability:
kg＝k∞·krg(Swm)
in the formula, k∞Is the rock absolute permeability, mD; k is a radical ofrg(Swm) As movable water saturation SwmAnd permeability retention rate krgThe relational expression (c) of (c).
For a compact water-containing gas reservoir, certain initial movable water is contained in a pore network space, the gas phase permeability is obviously influenced by the movable water saturation, and an empirical formula of the effective permeability under different absolute permeability and movable water saturation is established by regression by combining effective permeability and starting pressure gradient test data of a rock core under different movable water saturation conditions.
Example 5:
on the basis of the embodiment 3, the embodiment provides a method for judging whether the tight sandstone movable water-gas reservoir gas well has development value, and the step (2) is to determine the viscosity of the natural gas under the average pressure of the stratum
Figure BDA0002703686540000071
Viscosity mu with formation waterwDegree of movable water saturation SwmWeighting to obtain the comprehensive viscosity of the formation fluid
Figure BDA0002703686540000072
Figure BDA0002703686540000073
In the formula (I), the compound is shown in the specification,
Figure BDA0002703686540000074
viscosity of natural gas, cP, at the average pressure of the formation; mu.swFormation water viscosity, cP;
Figure BDA0002703686540000075
is the formation fluid integrated viscosity, cP; swmIs the formation mobile water saturation.
For dense water-bearing reservoirs, the formation fluids include natural gas and formation mobile water, and although the mobile water is very low in saturation, the apparent viscosity of the gas-water two-phase flow will be significantly affected by the presence of the mobile water, since the viscosity of water is much higher than that of natural gas. Thus for a tight water-bearing reservoir, the average viscosity of the formation fluid should be weighted by the natural gas viscosity at the average pressure of the formation and the saturation of the formation water viscosity:
example 6:
on the basis of example 3, the present example provides a method for judging tight sandstoneA method for judging whether a gas well of a flowing water gas reservoir has development value or not includes the step (3) of establishing a flowing boundary r based on radial flow stratum pressure distribution and starting pressure gradient, gas well production pressure difference, seepage characteristics and fluid parameterseFlow pressure p along with bottom holewThe variation relation of (1);
Figure BDA0002703686540000076
in the formula, pwIs bottom hole flowing pressure, MPa; p is a radical ofiIs the formation static pressure, MPa; k is a radical ofgIs the gas phase effective permeability, mD, of the rock;
Figure BDA0002703686540000077
is the formation fluid integrated viscosity, cP.
The method comprises the steps of enabling a compact water-containing gas reservoir to have a remarkable starting pressure effect, enabling each production pressure difference to correspond to a flow boundary, enabling the flow boundary of a gas well to be the actual control radius of the gas well, enabling the production pressure difference and the formation flow capacity to be main control factors of the control radius of the gas well, and establishing a change relation of the flow boundary along with the bottom hole flow pressure by combining the production pressure difference, the seepage characteristics and fluid parameters of the gas well.
Example 7:
on the basis of embodiment 3, the embodiment provides a method for judging whether a tight sandstone movable water-gas reservoir gas well has development value, and step (3) the gas well productivity qscAnd the movable water saturation degree SwmThe relationship of (A) is as follows:
Figure BDA0002703686540000081
in the formula, qscFor gas well production, m3/d；kgIs the gas phase effective permeability, mD, of the reservoir rock; h is the effective thickness of the reservoir, m; p is a radical ofiIs the formation static pressure, MPa; p is a radical ofwIs bottom hole flowing pressure, MPa; t is the formation temperature, K;
Figure BDA0002703686540000082
is the formation fluid integrated viscosity, cP;
Figure BDA0002703686540000083
is the mean formation gas eccentricity factor; r iseIs the gas well flow boundary, m; r iswIs the gas well borehole radius, m; s is the epidermal coefficient; swmIs the formation mobile water saturation.
For the compact water-containing gas reservoir, the influence of movable water on gas phase permeability, comprehensive viscosity of formation fluid and gas well control range must be considered, and based on the evaluation of the influence factors, a gas well productivity formula of the compact water-containing gas reservoir is established.
Wherein k isg＝k∞·krg(Swm)，
Figure BDA0002703686540000084
To obtain the following formula:
Figure BDA0002703686540000085
krg(Swm) As movable water saturation SwmAnd permeability retention rate krgThe permeability retention rate is the gas phase effective permeability kgAbsolute permeability k of rock∞The ratio of (a) to (b).
Example 8:
on the basis of the embodiment 1 or 2 or 3 or 4 or 5 or 6 or 7, the embodiment provides a method for judging whether the tight sandstone movable water-gas reservoir gas well has development value, which specifically comprises the following steps:
step one, establishing an effective permeability empirical formula by combining core gas-water flow test data
For a compact water-containing gas reservoir, certain initial movable water is contained in a pore network space, the gas phase permeability is obviously influenced by the movable water saturation, and an empirical formula of the effective permeability under different absolute permeability and movable water saturation is established by regression by combining effective permeability and starting pressure gradient test data under different movable water saturation conditions of a rock core:
kg＝k∞·krg(Swm)
step two, establishing the viscosity of the formation fluid under the formation condition
For dense water-bearing reservoirs, the formation fluids include natural gas and formation mobile water, and although the mobile water is very low in saturation, the apparent viscosity of the gas-water two-phase flow will be significantly affected by the presence of the mobile water, since the viscosity of water is much higher than that of natural gas. Thus for a tight water-bearing reservoir, the average viscosity of the formation fluid should be weighted by the natural gas viscosity at the average pressure of the formation and the saturation of the formation water viscosity:
Figure BDA0002703686540000091
step three, calculating the flowing boundary under each bottom hole flowing pressure based on the radial flowing stratum pressure distribution and the starting pressure gradient
The method comprises the following steps of (1) establishing a change relation formula of a flow boundary along with bottom hole flow pressure by combining production pressure difference, seepage characteristics and fluid parameters of the gas well, wherein the change relation formula comprises that (1) a compact water-containing gas reservoir has a remarkable starting pressure effect, each production pressure difference corresponds to one flow boundary, the flow boundary of the gas well is the actual control radius of the gas well, the production pressure difference and the formation flow capacity are main control factors of the control radius of the gas well:
Figure BDA0002703686540000092
step four, establishing a tight sandstone water-bearing gas reservoir gas well productivity calculation formula
For the compact water-containing gas reservoir, the influence of movable water on gas phase permeability, comprehensive viscosity of formation fluid and gas well control range must be considered, and based on the evaluation of the influence factors, a gas well productivity formula of the compact water-containing gas reservoir is established.
Figure BDA0002703686540000101
In the formula: q. q.sscFor gas well production, m3/d；kgIs the gas phase effective permeability, mD, of the reservoir rock; h is the effective thickness of the reservoir, m; p is a radical ofiIs the formation static pressure, MPa; p is a radical ofwIs bottom hole flowing pressure, MPa; t is the formation temperature, K;
Figure BDA0002703686540000102
is the formation fluid integrated viscosity, cP;
Figure BDA0002703686540000103
is the mean formation gas eccentricity factor; r iseIs the gas well flow boundary, m; r iswIs the gas well borehole radius, m; s is the epidermal coefficient; swmFormation mobile water saturation;
Figure BDA0002703686540000104
viscosity of natural gas, cP, at the average pressure of the formation; mu.swIs the formation water viscosity, cP.
The calculation principle of the flow boundary in the third step is as follows:
the production pressure drop will create a near-to-far pressure drop funnel in the formation, within which the formation pressure at various locations is proportional to the logarithm of the radial distance, i.e.:
Figure BDA0002703686540000105
in the formula: p is a radical ofeThe formation pressure at the boundary of the well control range is MPa; p is the formation pressure at any radial distance r, MPa; r is any radial distance, m.
Calculating the formation pressure at each radial distance: p is a radical ofriI ═ 0,1,2,. n, where:
pr0＝pw,prn＝pe
calculating the formation pressure gradient at each radial distance: g ri1, 2.., n, wherein:
gri＝(pri-pri-1)/(ri-ri-1)
and the radial distance is from near to far, and when the formation pressure gradient does not exceed the starting pressure gradient, the corresponding distance is the flow boundary corresponding to the bottom hole pressure:
Figure BDA0002703686540000106
in the formula: r isbIs the radial distance, m, of the gas well flow boundary; griIs the formation pressure gradient, m.
Well control range reThe inner reserves are single well geological reserves and the actual stratum flow range r under the current bottom hole pressurebThe reservoir in (c) is the single well recoverable reservoir (assuming the current bottom-hole pressure is higher than the abandoned bottom-hole pressure) from which the gas well recovery is estimated. At this time, the flow boundary reValue of rb。
Example 9:
this example illustrates the present invention in further detail by taking a block in a tight sandstone reservoir as an example.
Performing a plurality of groups of core flow test tests on a block in the tight sandstone water-bearing gas reservoir, wherein the original formation pressure p of the blocki33.5MPa, formation water viscosity, muwViscosity of natural gas at formation mean pressure of 0.28cP
Figure BDA0002703686540000114
Is 1.2656X 10-2cP。
1. Collecting the block test data and establishing the effective permeability empirical formula of the zone
Four cores, namely a core 51 well 2-1/125, a core x73 well 3-17/44, a core x29 well 2-5/133 and a core x124 well 5-13/47, are respectively selected, and the effective permeability experimental data are shown in table 1.
Table 1 effective permeability experimental data
Figure BDA0002703686540000111
According to effective permeability test data of 4 rock samples with different water saturations, empirical formulas of water saturation and permeability retention rate (gas phase effective permeability/rock absolute permeability) are regressed, and are respectively shown in the figures 1,2, 3 and 4.
And (3) according to effective permeability test data of the 4 rock samples in the block under different water saturation degrees, regressing an empirical formula of effective permeability to obtain an empirical formula of the ratio of the effective permeability to the absolute permeability of the compact reservoir in the block under the condition that movable water exists:
Figure BDA0002703686540000112
2. establishing an empirical formula of the viscosity of the formation fluid under the formation conditions of the block
Combining the block dynamic monitoring data to obtain the horizontal average viscosity of the natural gas and the stratum, and establishing a stratum fluid viscosity empirical formula of a natural gas and movable water coexisting system under the stratum condition according to saturation weighting:
Figure BDA0002703686540000113
3. establishing a block gas well flow boundary calculation empirical formula
1) The calculation principle is as follows: the production pressure drop will create a near-to-far pressure drop funnel in the formation, within which the formation pressure at various locations is proportional to the logarithm of the radial distance, i.e.:
Figure BDA0002703686540000121
in the formula: p is a radical ofeThe formation pressure at the boundary of the well control range is MPa; p is a radical ofwIs bottom hole flowing pressure, MPa; p is the formation pressure at any radial distance r, MPa; r iswIs the gas well borehole radius, m; r iseIs the gas well flow boundary (radial distance of well control range boundary), m; r is anyRadial distance, m.
Calculating the formation pressure at each radial distance: p is a radical ofriI ═ 0,1,2,. n, where:
pr0＝pw,prn＝pe
calculating the formation pressure gradient at each radial distance: g ri1, 2.., n, wherein:
gri＝(pri-pri-1)/(ri-ri-1)
and the radial distance is from near to far, and when the formation pressure gradient does not exceed the starting pressure gradient, the corresponding distance is the flow boundary corresponding to the bottom hole pressure:
Figure BDA0002703686540000122
in the formula: r isbIs the radial distance, m, of the gas well flow boundary; griIs the formation pressure gradient, m.
Well control range reThe inner reserves are single well geological reserves and the actual stratum flow range r under the current bottom hole pressurebThe reservoir in (c) is the single well recoverable reservoir (assuming the current bottom-hole pressure is higher than the abandoned bottom-hole pressure) from which the gas well recovery is estimated.
2) Block example calculation: the absolute permeability of reservoir rock in the block is 0.1-2.5 mD, the movable water saturation is about 0.2 at most, and three bottom hole flow pressures of 7.5 MPa, 5.0 MPa and 2.5MPa are set. Gas well flow boundaries are calculated from the combination of parameters, as shown in table 2:
Figure BDA0002703686540000123
Figure BDA0002703686540000131
obtaining an empirical formula of the flow boundary of the gas well in the work area by using a multiple regression analysis method:
Figure BDA0002703686540000132
the data show that formation water production has a significant effect on the flow boundaries of gas wells. The gas well flow boundary decreases rapidly at the initial water production, but diminishes as the formation is produced further. The reservoir formation research shows that the compact gas reservoir contains more water, and the occurrence of movable water in the middle and later periods of production is inevitable, so that the influence of formation effluent is required to be considered during capacity evaluation and development scheme preparation.
4. Establishing a productivity calculation equation of the block gas well
Based on gas-water flow experimental data of reservoir rock samples in the work area, combining with a seepage mechanics theoretical model, and according to the empirical formulas of the three influence factors, obtaining a gas well productivity calculation formula suitable for the reservoir in the block:
Figure BDA0002703686540000133
according to the obtained calculation formula of the gas well productivity of the block, calculating the gas well yield (or gas well non-resistance flow rate) under the combination of the typical reservoir and fluid parameters of the work area, as shown in table 3:
TABLE 3 calculation data table for gas well non-resistance flow in work area
Figure BDA0002703686540000134
Figure BDA0002703686540000141
The statistical calculation results show that the amplitude of the gas well productivity decreased by the formation water is very obvious, and the influence rule is shown in fig. 5. Therefore, for dynamic water saturation SwmAnd if the productivity retention rate is more than 15% and less than 0.2, judging that the gas well has no development value.
The above examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims and any design similar or equivalent to the scope of the invention.

Claims (8)

1. A method for judging whether a tight sandstone movable water-gas reservoir gas well has development value is characterized by comprising the following steps:
step 1) obtaining the gas well productivity qscAnd the movable water saturation degree SwmThe relational expression of (1);
step 2) let the movable water saturation SwmIs 0, according to gas well productivity qscAnd the movable water saturation degree SwmTo obtain the gas well productivity qsc0；
Step 3) calculating the saturation S of each movable waterwmCorresponding gas well productivity qscBy qsc/qsc0Obtaining the productivity retention rate;
step 4) obtaining movable water saturation SwmA graph relating to productivity retention;
step 5) when the movable water saturation SwmAnd when the productivity retention rate is more than 15% and less than 0.2, judging that the gas reservoir gas well has no development value.
2. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 1, wherein the gas well productivity q in the step 1) isscAnd the movable water saturation degree SwmIs given by the gas phase effective permeability k of the mobile water in the reservoirgComprehensive viscosity of formation fluid
Figure FDA0002703686530000011
And a flow boundary reThree influencing factors are obtained.
3. The method for judging whether the tight sandstone movable water-gas reservoir gas well has development value or not according to claim 1 or 2, wherein the step 1) is used for obtaining the yield q of the gas wellscAnd the movable water saturation degree SwmThe specific process of the relation of (1) is as follows:
(1) obtaining the gas phase effective permeability k of the rock according to the gas-water flow test data of the rock coregAnd the movable water saturation degree SwmAbsolute permeability k∞The relational expression of (1);
(2) according to the viscosity of natural gas under the average pressure of stratum
Figure FDA0002703686530000012
Formation water viscosity muwAnd the movable water saturation degree SwmObtaining the comprehensive viscosity of the formation fluid under the formation condition
Figure FDA0002703686530000013
(3) Establishing a flow boundary reFlow pressure p along with bottom holewThe variation relation of (1);
(4) according to the gas phase effective permeability k of the rockgComprehensive viscosity of formation fluid
Figure FDA0002703686530000014
And a flow boundary reEstablishing a compact sandstone water-bearing gas reservoir gas well productivity calculation formula to obtain the gas well productivity qscAnd the movable water saturation degree SwmThe relational expression (c) of (c).
4. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 3, wherein the method comprises the following steps: step (1) combines the gas phase effective permeability k of the rock under different movable water saturation conditions of the rock coregRegression establishes different absolute permeabilities k∞And movable water saturation SwmThe following empirical formula for effective permeability:
kg＝k∞·krg(Swm)
in the formula, k∞Is the rock absolute permeability, mD; k is a radical ofrg(Swm) As movable water saturation SwmAnd permeability retention rate krgThe relational expression (c) of (c).
5. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 3, wherein the method comprises the following steps: step (2) is carried out by measuring the viscosity of the natural gas under the average pressure of the stratum
Figure FDA0002703686530000021
Viscosity mu with formation waterwDegree of movable water saturation SwmWeighting to obtain the comprehensive viscosity of the formation fluid
Figure FDA0002703686530000022
Figure FDA0002703686530000023
In the formula (I), the compound is shown in the specification,
Figure FDA0002703686530000024
viscosity of natural gas, cP, at the average pressure of the formation; mu.swFormation water viscosity, cP;
Figure FDA0002703686530000025
is the formation fluid integrated viscosity, cP; swmIs the formation mobile water saturation.
6. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 3, wherein the method comprises the following steps: step (3) is to establish a flow boundary r based on the radial flow stratum pressure distribution and the starting pressure gradient, the gas well production pressure difference, the seepage characteristic and the fluid parametereFlow pressure p along with bottom holewThe variation relation of (1);
Figure FDA0002703686530000026
in the formula, pwIs bottom hole flowing pressure, MPa; p is a radical ofiIs the formation static pressure, MPa; k is a radical ofgIs the gas phase effective permeability, mD, of the rock;
Figure FDA0002703686530000027
is the formation fluid integrated viscosity, cP.
7. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 3, wherein the method comprises the following steps: step (3) gas well productivity qscAnd the movable water saturation degree SwmThe relationship of (A) is as follows:
Figure FDA0002703686530000031
in the formula, qscFor gas well production, m3/d；kgIs the gas phase effective permeability, mD, of the reservoir rock; h is the effective thickness of the reservoir, m; p is a radical ofiIs the formation static pressure, MPa; p is a radical ofwIs bottom hole flowing pressure, MPa; t is the formation temperature, K;
Figure FDA0002703686530000032
is the formation fluid integrated viscosity, cP;
Figure FDA0002703686530000033
is the mean formation gas eccentricity factor; r iseIs the gas well flow boundary, m; r iswIs the gas well borehole radius, m; s is the epidermal coefficient; swmIs the formation mobile water saturation.
8. The method for judging whether the tight sandstone mobile water-gas reservoir gas well has development value or not according to claim 3, wherein the method comprises the following steps: local formation pressure gradient griWhen the starting pressure gradient lambda is not exceeded, the corresponding distance rbIs the flow boundary r corresponding to the bottom hole pressuree：
rb＝r|gri≤λ
In the formula, rbIs the radial distance, m, of the gas well flow boundary; griIs the formation pressure gradient, m; λ is the starting pressure gradient, m.
CN202011031046.1A 2020-09-27 2020-09-27 Method for judging whether tight sandstone movable water-gas reservoir gas well has development value Active CN112257349B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011031046.1A CN112257349B (en) 2020-09-27 2020-09-27 Method for judging whether tight sandstone movable water-gas reservoir gas well has development value

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011031046.1A CN112257349B (en) 2020-09-27 2020-09-27 Method for judging whether tight sandstone movable water-gas reservoir gas well has development value

Publications (2)

Publication Number Publication Date
CN112257349A true CN112257349A (en) 2021-01-22
CN112257349B CN112257349B (en) 2022-10-04

Family

ID=74233544

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011031046.1A Active CN112257349B (en) 2020-09-27 2020-09-27 Method for judging whether tight sandstone movable water-gas reservoir gas well has development value

Country Status (1)

Country Link
CN (1) CN112257349B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113898338A (en) * 2021-10-26 2022-01-07 北京科技大学 Unconventional gas reservoir starting pressure gradient determination method and device
CN116245423A (en) * 2023-03-31 2023-06-09 西南石油大学 Water and gas reservoir development effect evaluation method considering phase permeability influence

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107975369A (en) * 2017-10-25 2018-05-01 中国石油天然气股份有限公司 A kind of carbonate gas reservoirs effective permeability Forecasting Methodology
CN110646332A (en) * 2019-10-22 2020-01-03 西南石油大学 Method for determining movable water saturation of gas-water interbed gas reservoir under high-temperature and high-pressure conditions
CN111236908A (en) * 2020-01-09 2020-06-05 西南石油大学 Multi-stage fractured horizontal well productivity prediction model and productivity sensitivity analysis method suitable for low-permeability tight gas reservoir

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107975369A (en) * 2017-10-25 2018-05-01 中国石油天然气股份有限公司 A kind of carbonate gas reservoirs effective permeability Forecasting Methodology
CN110646332A (en) * 2019-10-22 2020-01-03 西南石油大学 Method for determining movable water saturation of gas-water interbed gas reservoir under high-temperature and high-pressure conditions
CN111236908A (en) * 2020-01-09 2020-06-05 西南石油大学 Multi-stage fractured horizontal well productivity prediction model and productivity sensitivity analysis method suitable for low-permeability tight gas reservoir

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
叶礼友等: "致密砂岩气藏产水机理与开发对策", 《天然气工业》 *
汪周华等: "低渗气藏考虑非线性渗流特征的稳态产能方程", 《天然气工业》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113898338A (en) * 2021-10-26 2022-01-07 北京科技大学 Unconventional gas reservoir starting pressure gradient determination method and device
CN113898338B (en) * 2021-10-26 2022-04-05 北京科技大学 Unconventional gas reservoir starting pressure gradient determination method and device
CN116245423A (en) * 2023-03-31 2023-06-09 西南石油大学 Water and gas reservoir development effect evaluation method considering phase permeability influence
CN116245423B (en) * 2023-03-31 2023-11-17 西南石油大学 Water and gas reservoir development effect evaluation method considering phase permeability influence

Also Published As

Publication number Publication date
CN112257349B (en) 2022-10-04

Similar Documents

Publication Publication Date Title
CN109441422B (en) Shale gas well spacing optimization mining method
CN111581786B (en) Well test interpretation method of well test interpretation model for analyzing fracture-cave series-mode double-hole composite reservoir
CN109838230B (en) Quantitative evaluation method for oil reservoir water flooded layer
Raghavan Well test analysis: Wells producing by solution gas drive
CN110334431A (en) A kind of low permeability tight gas reservoir single well controlled reserves calculating and remaining gas analysis method
CN107462936B (en) Utilize the method for pressure monitoring Data Inversion low permeability reservoir non-Darcy percolation law
CN111236908A (en) Multi-stage fractured horizontal well productivity prediction model and productivity sensitivity analysis method suitable for low-permeability tight gas reservoir
Sanghani et al. Rheology of foam and its implications in drilling and cleanout operations
CN107045671A (en) Water-producing gas well hydrops Risk Forecast Method
CN105840187A (en) Method for calculating staged fracturing productivity of compact reservoir horizontal well
Nazari Moghaddam et al. Steady-state relative permeability measurements of tight and shale rocks considering capillary end effect
RU2301886C1 (en) Reservoir conductivity determination method
CN111353205B (en) Method for calculating formation pressure and dynamic productivity of water-producing gas well of tight gas reservoir
CN108133080B (en) Heterogeneous fractured shale gas reservoir numerical simulation method considering unsteady adsorption
CN112257349B (en) Method for judging whether tight sandstone movable water-gas reservoir gas well has development value
CN114372352B (en) Method for predicting peak regulation capacity of gas storage of complex fault block oil reservoir through seepage-temperature double-field coupling numerical simulation
CN110656915B (en) Shale gas multi-section fracturing horizontal well multi-working-system productivity prediction method
CN107526891B (en) Polymer flooding large-pore oil reservoir well testing analysis method
CN113484216B (en) Method for evaluating water phase flowback rate and reasonable flowback pressure difference of tight sandstone gas reservoir
CN104695952B (en) The means of interpretation and solution release system of unconventional gas reservoir formation parameter
Yi et al. A comprehensive model of fluid loss in hydraulic fracturing
CN112036097B (en) Capacity calculation method for water-lock gas well
CN112561223B (en) Quantitative evaluation method for oil and gas well yield-increasing potential
CN113530534B (en) Reservoir reconstruction method and device
CN111364982B (en) Value method for oil saturation of tight sandstone

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