CN112253052B - Natural gas exploitation method and natural gas exploitation system - Google Patents
Natural gas exploitation method and natural gas exploitation system Download PDFInfo
- Publication number
- CN112253052B CN112253052B CN202011123648.XA CN202011123648A CN112253052B CN 112253052 B CN112253052 B CN 112253052B CN 202011123648 A CN202011123648 A CN 202011123648A CN 112253052 B CN112253052 B CN 112253052B
- Authority
- CN
- China
- Prior art keywords
- gas
- well
- water
- matrix
- wells
- 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.)
- Active
Links
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 268
- 239000003345 natural gas Substances 0.000 title claims abstract description 134
- 238000000034 method Methods 0.000 title claims abstract description 42
- 239000007789 gas Substances 0.000 claims abstract description 338
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 136
- 238000005553 drilling Methods 0.000 claims abstract description 70
- 239000011159 matrix material Substances 0.000 claims description 74
- 238000004519 manufacturing process Methods 0.000 claims description 28
- 230000035699 permeability Effects 0.000 claims description 23
- 230000015572 biosynthetic process Effects 0.000 claims description 15
- 239000011435 rock Substances 0.000 claims description 11
- 230000001133 acceleration Effects 0.000 claims description 6
- 230000005484 gravity Effects 0.000 claims description 6
- 230000035945 sensitivity Effects 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 2
- 230000009467 reduction Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 15
- 239000012071 phase Substances 0.000 description 15
- 238000005755 formation reaction Methods 0.000 description 11
- 238000010276 construction Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
- DCRGHMJXEBSRQG-UHFFFAOYSA-N 1-[1-(cyclooctylmethyl)-5-(hydroxymethyl)-3,6-dihydro-2H-pyridin-4-yl]-3-ethyl-2-benzimidazolone Chemical compound O=C1N(CC)C2=CC=CC=C2N1C(CC1)=C(CO)CN1CC1CCCCCCC1 DCRGHMJXEBSRQG-UHFFFAOYSA-N 0.000 description 4
- 230000005251 gamma ray Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- 230000005465 channeling Effects 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000003306 harvesting Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000009545 invasion Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/30—Specific pattern of wells, e.g. optimising the spacing of wells
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Data Mining & Analysis (AREA)
- General Physics & Mathematics (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Algebra (AREA)
- Computational Mathematics (AREA)
- Databases & Information Systems (AREA)
- Software Systems (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Analysis (AREA)
- Geophysics And Detection Of Objects (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The application discloses a natural gas exploitation method and a natural gas exploitation system, and belongs to the field of oil and gas exploration and development. The method comprises the following steps: and in the gas-containing trap with the water-gas reservoir, drilling according to the sequence from the low part of the structure to the high part of the structure to obtain a target well pattern. The target pattern includes a centerwell and at least two rings of wells distributed around the centerwell. The well heads of the wells belonging to different rings and the central well in at least two rings of wells are different in height. The height of the wellhead is the height of the wellhead relative to the bottom of the gas-containing trap; and collecting natural gas through the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
Description
Technical Field
The application relates to the field of oil and gas exploration and development, in particular to a natural gas exploitation method and a natural gas exploitation system.
Background
A water-gas reservoir usually comprises at least one gas-containing trap, which refers to a location where natural gas can be prevented from continuing to migrate and can accumulate therein, and where water also accumulates. When water and gas reservoirs are developed by adopting different development modes, different water invasion dynamic laws can appear, so that the recovery ratio of the collected natural gas is different.
The structure containing the balloon is approximately conical. The high part of the structure containing the gas trap is the part of the gas trap close to the top, and the low part of the structure containing the gas trap is the part of the gas trap close to the bottom. The highest amount of natural gas accumulates in the high points of the formations containing gas traps, since natural gas is less dense than water. Currently, to quickly reach a predetermined production scale, natural gas is typically collected by deploying wells from high sites of the formation containing gas traps to low sites of the formation. However, after a period of production, the natural gas is collected, which causes the bottom hole pressure of the well to drop rapidly, forming a plurality of pressure drop funnels, the water in the gas trap can be pushed to the bottom hole rapidly, the well can be flooded, and a water lock phenomenon can occur to block the gas flow, which causes the yield of the well to drop. Natural gas collection is inefficient.
Disclosure of Invention
The application provides a natural gas exploitation method and a natural gas exploitation system, which can improve the efficiency of natural gas acquisition. The technical scheme is as follows:
according to an aspect of the present application, there is provided a method of natural gas production, the method comprising:
drilling in a gas-containing trap with a water and gas reservoir according to the sequence from a low construction part to a high construction part to obtain a target well pattern, wherein the target well pattern comprises a central well and at least two circles of wells distributed around the central well, the heights of well heads of the wells belonging to different circles and the central well are different from each other, and the height of the well head is the height of the well head relative to the bottom of the gas-containing trap;
collecting natural gas through the target well pattern.
Optionally, the target well pattern comprises wells with gradually increasing height from outside to inside in a nesting order in horizontal section.
Optionally, the drilling in the gas-containing trap with the water gas reservoir in the order from the low position of the formation to the high position of the formation to obtain the target well pattern includes:
drilling the gas-containing trap for the ith time to obtain an ith trap;
drilling for the (i + 1) th time on the gas-containing trap to obtain an (i + 1) th circle of well, wherein the (i) th circle of well is positioned at the periphery of the (i + 1) th circle of well, and the distance between the well mouth of any one of the (i) th circle of well and the circle of the (i + 1) th circle of well is a target distance along the direction of a connecting line between the well mouth of any one of the (i) th circle of well and the top of the gas-containing trap;
and n is more than or equal to 1 and less than or equal to n-1, n is the number of turns of the at least two turns of wells, the linear distance between well mouths of m pairs of wells in any one turn of wells in the at least two turns of wells is the target distance, the linear distance between well mouths of the remaining pair of wells is less than or equal to the target distance, and each pair of wells is two adjacent wells in any one turn of wells.
Optionally, the wellhead of the 1 st well is located at the lowest part of the gas trap, and the wellhead of the 1 st well is arranged along the edge of the bottom of the gas trap.
Optionally, the method further comprises:
and determining the target distance according to a continuous seepage function of the gas-water two-phase containing the gas trap, wherein the function is used for reflecting the seepage characteristics between the water and the natural gas in the gas trap.
Optionally, the determining the target distance according to the continuous seepage function of the gas-water two-phase containing the gas trap includes:
determining the gas saturation, the water saturation and the gas pressure of the trap according to the function;
and determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as the target distance.
Optionally, the wellhead of the centerwell is located at the top of the gas-containing trap.
Optionally, the aqueous vapor reservoir includes at least two gas-containing traps, the method further comprising:
and drilling according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap to obtain the target well pattern corresponding to each gas-containing trap in the at least two gas-containing traps.
Optionally, the drilling in the gas-containing trap with the water gas reservoir in the order from the low position of the formation to the high position of the formation to obtain the target well pattern includes:
and drilling the central well after drilling to obtain the at least two circles of wells.
According to another aspect of the present application, there is provided a natural gas production system, the system comprising:
drilling in a gas-containing trap with a water and gas reservoir according to the sequence from a construction low part to a construction high part to obtain a target well pattern, wherein the target well pattern comprises a central well and at least two circles of wells distributed around the central well, the heights of well heads of the wells belonging to different circles in the at least two circles of wells are different from each other, and the height of the well head is the height of the well head relative to the bottom of the gas-containing trap;
and the gas production equipment is used for collecting natural gas through the target well pattern.
Optionally, the target well pattern comprises wells, and the heights of the well heads are gradually increased according to the nesting sequence from outside to inside in the horizontal section.
Optionally, the drilling apparatus is for:
drilling the gas-containing trap for the ith time to obtain an ith trap;
drilling for the (i + 1) th time on the gas-containing trap to obtain an (i + 1) th circle of well, wherein the (i) th circle of well is positioned at the periphery of the (i + 1) th circle of well, and the distance between the well mouth of any well and the circle of the (i + 1) th circle of well is a target distance along the direction of the connecting line between the well mouth of any well in the (i) th circle of well and the top of the gas-containing trap;
and i is more than or equal to 1 and less than or equal to n-1, n is the number of turns of the at least two turns of wells, the linear distance between well mouths of m pairs of wells in any turn of the at least two turns of wells is the target distance, the linear distance between well mouths of the remaining pair of wells is less than or equal to the target distance, and each pair of wells is two adjacent wells in any turn of the wells.
Optionally, the wellhead of the 1 st well is located at the lowest part of the structure of the gas-containing trap, and the wellheads of the 1 st well are arranged along the edge of the bottom of the gas-containing trap.
Optionally, the system further comprises:
and the computer equipment is used for determining the target distance according to a continuous seepage function of the gas-water two phases containing the gas trap, wherein the function is used for reflecting seepage characteristics between water and natural gas in the gas trap.
Optionally, the computer device is configured to:
determining the gas saturation, the water saturation and the gas pressure of the trap according to the function;
and determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as the target distance.
Optionally, the wellhead of the centerwell is located at the top of the gas-containing trap.
Optionally, the hydrocarbon reservoir comprises at least two gas-containing traps, the drilling apparatus being configured to:
and drilling according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap to obtain the target well pattern corresponding to each gas-containing trap in the at least two gas-containing traps.
Optionally, the drilling apparatus is for:
and drilling the central well after drilling to obtain the at least two circles of wells.
The beneficial effect that technical scheme that this application provided brought includes at least:
and drilling according to the sequence from the construction low part to the construction high part to obtain a target well pattern, and collecting natural gas through the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a schematic illustration of a water vapor reservoir provided by an embodiment of the present application;
FIG. 2 is a schematic flow diagram of a method for natural gas production provided by an embodiment of the present application;
FIG. 3 is a schematic flow diagram of another method of natural gas production provided by an embodiment of the present application;
FIG. 4 is a schematic illustration of an implementation of drilling to obtain a target well pattern provided by an embodiment of the present application;
FIG. 5 is a schematic illustration of a top view of a target well pattern provided by an embodiment of the present application;
FIG. 6 is a schematic cross-sectional view of a target well pattern provided by an embodiment of the present application;
FIG. 7 is a schematic diagram of a process for solving a linearized differential equation set provided by an embodiment of the present application;
FIG. 8 is a schematic illustration of analyzing gas saturation of gas traps provided by an embodiment of the present application;
FIG. 9 is a schematic illustration of analyzing water saturation with gas traps provided in an embodiment of the present application;
FIG. 10 is a schematic diagram of analyzing a pressure of a gas containing a trap provided in an embodiment of the present application;
FIG. 11 is a schematic illustration of a natural gas production system according to an embodiment of the present disclosure;
fig. 12 is a schematic structural diagram of another natural gas production system provided in an embodiment of the present application.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
To facilitate understanding of the methods provided by the embodiments of the present application, first, terms referred to in the embodiments of the present application will be described:
and (3) water and gas storage: a reservoir is a basic unit of oil-gas accumulation on the earth's crust, with an independent pressure system and a uniform oil-water interface accumulation. A reservoir is a reservoir when only natural gas collects in its traps. By a water-gas reservoir is meant a gas reservoir in which water is present in the trap that collects the natural gas.
Air-containing trap: the gas-containing trap refers to a place where natural gas can be prevented from continuously moving and gathering, and water also gathers in the gas-containing trap with a water-gas reservoir. Fig. 1 is a schematic diagram of a water-gas reservoir provided in an embodiment of the present application. As shown in fig. 1, the existing moisture reservoir 100 includes three traps including a first trap 101, a second trap 102, and a third trap 103. Natural gas usually collects in high-rise areas of the structure containing gas traps, below which water collects.
The embodiment of the application provides a natural gas exploitation system, includes: the system comprises computer equipment (also called an upper computer), drilling equipment and gas production equipment, wherein the computer equipment is used for controlling the drilling equipment to drill to obtain a target well pattern and controlling the gas production equipment to collect natural gas through the target well pattern. Fig. 2 is a schematic flow chart of a natural gas production method provided by an embodiment of the present application, which may be performed by the natural gas production system. As shown in fig. 2, the method includes:
The target pattern includes a centerwell and at least two rings of wells distributed about the centerwell. The well heads of each well in each circle of wells are arranged according to a circle or an ellipse, or are arranged in an approximate circle or an ellipse. The well heads of the wells belonging to different rings and the central well in the at least two rings of wells are different in height. Illustratively, with continued reference to fig. 1, the target well pattern for the first trap 101 has a higher wellhead height for the wells in the outer wells than the wells in the inner wells. The well head height of the central well is higher than the well head height of the wells in each circle of wells. The height of the wellhead is the height of the wellhead relative to the bottom of the gas-containing trap. The structure of the gas containing trap is similar to a cone, and the bottom of the gas containing trap is the bottom of the cone.
Optionally, when the water reservoir contains a plurality of traps, the computer device controls the drilling device to drill in each gas-containing trap according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap (that is, the sequence from the low-position to the high-position of the top of the gas-containing trap), so as to obtain the target well pattern corresponding to each gas-containing trap. Wherein the height of the top of the high position air containing trap is higher than that of the top of the low position air containing trap. As shown in fig. 1, as the heights of the tops of the third gas-containing trap 103, the first gas-containing trap 101 and the second gas-containing trap 102 are sequentially increased, the third gas-containing trap 103, the first gas-containing trap 101 and the second gas-containing trap 102 are sequentially drilled to obtain a target well pattern corresponding to each gas-containing trap.
And the computer equipment controls the gas production equipment to collect natural gas from the outer ring well to the inner ring well in sequence. And then collecting natural gas through the central well.
In summary, the natural gas mining method provided by the embodiment of the application drills according to the sequence from the low-structure part to the high-structure part to obtain the target well pattern, and natural gas is collected through the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
Fig. 3 is a schematic flow diagram of another gas production method provided by embodiments of the present application, which may be performed by the gas production system. As shown in fig. 3, the method includes:
and 301, acquiring the trap containing the moisture and gas reservoir.
Acquiring the gas-containing traps of the water-gas reservoir refers to determining the number of the gas-containing traps included in the water-gas reservoir and determining relevant parameters of the gas-containing traps of the water-gas reservoir, wherein the relevant parameters comprise information which is used for reflecting the characteristics of water and natural gas gathered inside the gas-containing traps, such as the seepage velocity of natural gas in the gas-containing traps, the seepage velocity of water, the relative permeability between the natural gas and the water, and the like. And the computer equipment acquires the gas-containing trap of the water-gas reservoir, is used for determining a target well pattern corresponding to the gas-containing trap, and controls the drilling equipment to drill to obtain the target well pattern, so that the natural gas in the gas-containing trap is collected. Optionally, one aqueous vapor reservoir comprises one gas-containing trap, or one aqueous vapor reservoir comprises a plurality of gas-containing traps. When the water and gas reservoir is explored, the number of the gas traps included in the water and gas reservoir and the related parameters of the gas traps can be determined.
And 302, drilling in the gas trap with the water-gas reservoir according to the sequence from the low part of the structure to the high part of the structure to obtain a target well pattern.
The target pattern includes a centerwell and at least two rings of wells distributed around the centerwell. The well heads of the wells belonging to different rings and the central well in the at least two rings of wells are different in height from each other. The height of the wellhead is the height of the wellhead relative to the bottom of the gas-containing trap.
Optionally, the target pattern comprises wells having progressively increasing wellhead heights in nested order from outside to inside in horizontal cross-section. Namely, the inner ring well in two adjacent rings of wells is positioned in the area enclosed by the outer ring well. And the height of the well mouth of each well in the outer ring well is lower than that of each well in the inner ring well.
Optionally, the computer device, when controlling the drilling device to drill the target well pattern, drills each circle of wells in the target well pattern in order from the outer circle of wells to the inner circle of wells, thereby obtaining the target well pattern. As shown in fig. 4, it is assumed that the ith and (i + 1) th wells in the target well pattern are two adjacent wells. Wherein i is more than or equal to 1 and less than or equal to n-1, n is the number of turns of at least two turns of wells included in the target well pattern, and i and n are positive integers. Taking the two circles as an example to explain the implementation process of step 302, the drilling process of the ith circle of well and the (i + 1) th circle of well may be referred to as the drilling process of any other adjacent two circles in the target well pattern. Step 302 includes the following steps 3021 and 3022:
in step 3021, the ith drilling is performed on the gas trap to obtain the ith well.
In step 3022, drilling is performed for the (i + 1) th time on the gas-containing trap to obtain the (i + 1) th round of well. The ith circle of wells are positioned at the periphery of the (i + 1) th circle of wells, and the height of the well mouth of each well in the ith circle of wells is lower than that of each well mouth in the (i + 1) th circle of wells.
Referring to the foregoing step 3021 and step 3022, the computer device drills at least two circles of wells in a sequence from outside to inside and from low to high, so as to obtain a target well pattern. For example, the computer device controls the drilling device to drill according to the sequence of the 1 st circle of well, the 2 nd circle of well and the 3 rd circle of well to obtain a target well pattern, the obtained target well pattern comprises the 3 th circle of well, the 3 rd circle of well is in the area enclosed by the 2 nd circle of well, the 2 nd circle of well is in the area enclosed by the 1 st circle of well, the height of the well head of the 1 st circle of well is smaller than the height of the well head of the 2 nd circle of well, and the height of the well head of the 2 nd circle of well is smaller than the height of the well head of the 3 rd circle of well.
And in the direction of the connecting line of the well mouth of any well in the ith circle of wells and the top of the gas containing trap, the distance between the well mouth of any well and the circle of the (i + 1) th circle of wells is the target distance. Namely, after the computer equipment controls the drilling equipment to drill to obtain the outer ring well, the position of the ring of the inner ring well adjacent to the outer ring well can be determined according to the target position obtained by moving the wellhead of each well in the outer ring well towards the top of the gas-containing trap along the direction of the connecting line by the target distance. Optionally, the maximum transmission distance of the natural gas containing gas trap is the target distance. The top of the trap is the location of the apex of the cone to which the trap approximates.
And for any circle of wells in at least two circles of wells included by the target well pattern, the linear distance of the well mouths of m pairs of wells is the target distance, and the linear distance of the well mouths of the rest pairs of wells is smaller than or equal to the target distance. Each pair of wells is two adjacent wells in any circle of wells. After the position of a circle (such as a circle or an ellipse) where any circle of well in the target well pattern is located is determined, the computer equipment controls the drilling equipment to drill at the position of the circle according to the target distance, and therefore any circle of well in the target well pattern is obtained. Optionally, the computer device controls the drilling device to drill at any one of the locations of the circle, resulting in a first well of the circle. And then drilling is continued according to the advancing direction of the water in the gas-containing trap, so that all wells in the trap are obtained. Each well in the target pattern is drilled to a depth above the water level in the gas-containing trap. The computer device allows for acceptable errors (e.g., mechanical errors or manual errors) when controlling the drilling equipment to drill the pattern based on the target distance. Illustratively, when the computer device controls the drilling device to drill the 2 nd circle well in the target well pattern, the linear distance between every two of the 1 st well and the 2 nd well, the 2 nd well and the 3 rd well and the 4 th well is the target distance. When a 5 th well is drilled, drilling is carried out at the position of the circle of the 2 nd circle of well according to the fact that the linear distance between the 5 th well and the 4 th well is equal to the target distance, and the linear distance between the 5 th well and the 1 st well obtained through drilling is smaller than or equal to the target distance.
Optionally, the wellhead of the 1 st well is located at the lowest part of the structure of the gas-containing trap, and the wellheads of the 1 st well are arranged along the edge of the bottom of the gas-containing trap, that is, the 1 st well is located at the edge of the bottom of the gas-containing trap. The wellhead arrangement of the 1 st well in the target well pattern forms the circle of the 1 st well. Optionally, the computer device controls the drilling device to drill at any position on the edge of the bottom containing the gas trap to obtain a first well in the 1 st round, and then continues to drill according to the target distance to obtain the 1 st round.
Optionally, the wellhead of the centerwell is located at the top of the gas containing trap. This allows for more accurate collection of natural gas, since the top containing gas traps collects the most natural gas.
Optionally, the computer device controls the drilling device to drill the central well after drilling for at least two rounds of the well. The computer equipment controls the drilling equipment to drill in the gas containing trap to obtain each trap well, and then drill in the central well to obtain the target well pattern.
Illustratively, FIG. 5 is a schematic top view of a target well pattern provided by embodiments of the present application. As shown in fig. 5, the target well pattern corresponding to the gas trap 50 includes a 1 st well 501, a 2 nd well 502, a 3 rd well 503, and a center well 504. The well mouth of the 1 st well 501 is located at the lowest part of the structure containing the gas trap 50, and the well mouth of the 1 st well 501 is arranged to form the ring where the 1 st well 501 is located. The 2 nd well 502 is in the area enclosed by the 1 st well 501, and the 3 rd well 503 is in the area enclosed by the 2 nd well 502. The linear distance between every two wells in the 1 st circle of wells 501 is the target distance, the linear distance between every two wells in the 2 nd circle of wells 502 is the target distance, and the linear distance between every two wells in the 3 rd circle of wells 503 is the target distance. The centerwell 504 is located at the top of the gas containing trap 50. The central well 504 is in the area enclosed by the 3 rd well 503.
Illustratively, FIG. 6 is a schematic cross-sectional view of the target well pattern shown in FIG. 5. As shown in fig. 6, the well heads of the wells in the 1 st well 501 are located at the lowest part of the structure containing the gas trap 50, and the well heads of the wells in the 1 st well 501 are arranged to form the circle in which the 1 st well 501 is located. The distance between each well in the 1 st circle of wells 501 in the direction from the well to the top of the gas containing trap and the circle where the 2 nd circle of wells 502 is located is a target distance, and the distance between each well in the 2 nd circle of wells 502 in the direction from the well to the top of the gas containing trap and the circle where the 3 rd circle of wells 503 is a target distance. The centerwell 504 is located at the top of the gas trap 50 and each well in the 3 rd ring of wells 503 is less than the target distance from the centerwell 504 in the direction from the well to the top of the gas trap. The well head height of the central well 504 is higher than that of the 3 rd circle well 503.
The computer device can control the drilling device to drill in the order of the 1 st well 501, the 2 nd well 502, the 3 rd well 503 and the central well 504, so as to obtain the target well pattern shown in fig. 5 and 6.
Optionally, the computer device determines the target distance from a continuous seepage function of gas-water two phases containing the gas trap, the function reflecting seepage characteristics between water and natural gas in the gas trap. The computer device is capable of determining the gas saturation, the water saturation, and the gas pressure of the gas trap from the function. And then determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as a target distance. The maximum distance for natural gas propagation refers to the distance that natural gas can be propagated after the well for collecting natural gas finishes natural gas collection. The natural gas is drilled into the target well pattern according to the maximum natural gas propagation distance, each well in the target well pattern can be guaranteed to continuously collect the natural gas, and the efficiency of collecting the natural gas is improved.
Illustratively, the computer device establishes a gas-water two-phase continuous seepage function comprising a matrix system function and a fracture system function, wherein the matrix system function satisfies:
wherein, K m∞ The Kjeldahl permeability of the matrix is 10 -3 μm2。K rmg Is the relative permeability of the gas in the matrix. Rho mg The density of the gas in the matrix is given in kg/m 3. Mu.s mg The viscosity of the gas in the matrix is expressed in mPas. b is the slip factor of the matrix rock in MPa.
Is the average pressure of the gas in MPa.
Is the pressure gradient of the gas in the matrix, in MPa/m. g is the acceleration of gravity in m/s 2. D is the buried depth in m. Lambda [ alpha ] mg Is the starting pressure gradient of the gas in the matrix, in MPa/m. F g Is qiVolume cross flow in m 3 。q mg Is the gas quantity in the matrix system, and the unit is m 3 。φ m The unit is f (floating point number) for the porosity of the substrate. S. the mg The saturation of the gas in the matrix is given in f. K m Permeability as a matrix in 10 -3 μm2。K rmw Is the relative permeability of water in the matrix. Rho mw The density of water in the matrix is in kg/m 3. Mu.s mw The viscosity of water in the matrix is expressed in mPas.
Is the pressure gradient of water in the matrix, in MPa/m.
The overlying pressure gradient of the rock is a matrix system and has the unit of MPa/m. Lambda [ alpha ] mw Is the starting pressure gradient of water in the matrix, in MPa/m. F w Is the flow cross-over of water in m 3 。q mw The amount of water in the matrix system is m 3 。S mw Is the water saturation in the matrix in units of f.
The fracture system function satisfies:
wherein, B is a gas non-Darcy coefficient and has no dimension. K f0 The initial permeability of the fracture is given in 10 -3 μm2。p e -m The stress sensitivity coefficient is given in f. K rfg Is the relative permeability of the gas in the fracture. Rho fg The density of the gas in the cracks is expressed in kg/m 3. Mu.s fg The viscosity of the gas in the fracture is expressed in mPas.
The pressure gradient of the gas in the fracture is given in MPa/m. ρ is a unit of a gradient fg The density of the gas in the fracture is expressed in kg/m 3. g is the acceleration of gravity in m/s 2.
The unit is m for the depth variation. Lambda [ alpha ] fg The gas in the fracture initiates a pressure gradient in units of MPa/m. F g The unit is m3 for the blow-by flow of gas. q. q.s fg The gas amount in the fracture system is m 3. Phi is a unit of f The porosity of the fracture system is given in f. S fg The gas saturation in the fracture system is given in f. K is rfw Is the relative permeability of water in the fracture. Rho fw The density of water in the fracture is in kg/m 3. Mu.s fw The viscosity of water in the fracture is expressed in mPas.
The pressure gradient of the water in the fracture is given in MPa/m.
The unit is MPa/m, which is the overlying pressure gradient of the rock in the fracture system. Lambda [ alpha ] fw The starting pressure gradient of the water in the fracture is given in MPa/m. F w The unit is m3 for the cross-flow of water. q. q.s fw The amount of water in the fracture system is given in m 3. S. the fw Water saturation in the fracture system is given in f.
Among the above functions, the gas channeling amount F of the matrix system g Satisfies the following conditions:
wherein, K m Permeability as a matrix in 10 -3 μm2。μ g The viscosity of the gas is expressed in mPas. p is a radical of mg The gas pressure in the matrix system is in MPa. p is a radical of fg The gas pressure in the fracture system is in MPa. σ is the flow coefficient, representing the flow capacity, without units.
Flow rate of water channeling F w Satisfies the following conditions:
wherein, K m Permeability as a matrix in 10 -3 μm2。μ w The viscosity of water is expressed in mPas. p is a radical of mw The water pressure in the matrix system is in MPa. p is a radical of fw The water pressure in the fracture system is in MPa. σ is the flow coefficient, representing the flow capacity, without units.
When exploring a water-gas reservoir, the computer device is able to determine the relevant parameters corresponding to the gas traps of the water-gas reservoir.
Because very active water is gathered in the gas-containing trap, the reservoir gas-water boundary can keep the pressure from dropping. The outer boundary containing the trap is a constant pressure boundary, and the expression of the pressure magnitude is:
For the inner boundary containing the air trap, adopting fixed bottom hole flowing pressure, wherein the expression of the pressure is as follows:
When the pressure containing the trap changes with time, it is also necessary to determine the pressure distribution at the initial state. The initial conditions for example of pressure are:
p (x, y, z,0) — Φ (x, y, z, t), which is a pressure function at the initial time, indicates the pressure at the x, y, z position, and t — 0 time.
The initial distribution of water saturation is also determined when the gas phase and the water phase flow. The initial conditions for example for water saturation are:
S w0 ＝S w (x, y, z) which is a gas saturation function at the initial time, indicating the gas saturation at the x, y, z position at the initial time.
And the computer equipment calculates the gas-water two-phase seepage function by a finite difference method. A difference format of fracture and matrix system continuity equations can be obtained, wherein the difference format of the fracture system gas phase continuity equation is:
where Δ T is the time difference. P fg Is the gas pressure in the fracture system. Gamma ray fg ＝ρ fg g。V ijk Is the volume of a certain unit body (horizontal and vertical). Δ t is the time interval.
The difference format of the continuity equation of the water phase of the fracture system can be obtained by the same method as follows:
wherein, P fw The pressure of the fracture system water. P fc Overburden pressure on rock for a fracture system. Gamma ray fw ＝ρ fw g。
The differential format of the continuity equation of the gas phase of the matrix system can be obtained by the same method as follows:
wherein, P mg Is the matrix system gas pressure. Gamma ray mg ＝ρ mg g。
The difference format of the continuity equation of the aqueous phase of the matrix system can be obtained by the same method as follows:
where D is the buried depth in m. P mw Is the pressure of the water in the matrix system. P mc Overburden pressure is applied to the rock of the matrix system. Gamma ray mw ＝ρ mw g。
After the partial differential equation is subjected to differential dispersion, the partial differential equation is still relatively complex and is inconvenient to solve. Therefore, the above equation needs to be linearized. The bottom surface containing the trap is divided into a plurality of grid points, implicit solving pressure is adopted for each grid point, capillary pressure and conductivity coefficient are explicitly valued, and solving of the pressure, water saturation and gas saturation is alternately carried out. The linear difference equation system of the fracture system is finally obtained as follows:
h ijk δp i,j,k-1 +a ijk δp i,j-1,k +b ijk δp i-1,j,k +c ijk δp i,j,k +d ijk δp i+1,j,k +e ijk δp i,j+1,k +l ijk δp i,j,k+1 ＝g ijk ；
similarly, the linear differential equation set of the matrix system can be obtained as follows:
h ijk δp i,j,k-1 +a ijk δp i,j-1,k +b ijk δp i-1,j,k +c ijk δp i,j,k +d ijk δp i+1,j,k +e ijk δp i,j+1,k +l ijk δp i,j,k+1 ＝g ijk ；
wherein i represents a certain grid point in the horizontal x direction, j represents a certain grid point in the horizontal y direction, and k represents a certain grid point in the vertical z direction. a. b, c, d, e, g, h, l represent coefficients, and p represents a pressure value at a certain grid point.
And the computer equipment solves the linearized differential equation set of the fracture system and the linearized differential equation set of the matrix system, so that the gas saturation, the water saturation and the gas pressure of the gas trap can be determined. By way of example, fig. 7 is a schematic diagram of a process for solving a linearized differential equation set provided in an embodiment of the present application. As shown in fig. 7, the computer device performs gridding processing on the bottom surface containing the balloon closure, and reads the phase permeation and capillary force data. Then, the step length (unit) of the acquisition time and the maximum value of the acquisition time are read in, and the initial value of the acquisition time is made to be 0. And then determining the gas pressure containing the air trap when t is equal to 0, and starting to circularly accumulate the acquisition time according to the time step. And after the acquisition time is accumulated for one time, calculating the gas pressure, the water saturation and the gas saturation of the trap, accumulating the acquisition time step for one time again, and calculating the gas pressure, the water saturation and the gas saturation again until the corresponding gas pressure, the water saturation and the gas saturation are calculated according to the total acquisition time.
Illustratively, fig. 8 is a schematic diagram for analyzing gas saturation of a gas trap provided in an embodiment of the present application. As shown in fig. 8, the computer device can calculate the change of the gas saturation of the gas trap with time by using the method, so as to obtain a schematic diagram of the gas saturation of the analysis gas trap. The grid in the figure forms the bottom surface containing the balloon. FIG. 8 can reflect the distribution of gas saturation with gas traps.
Illustratively, fig. 9 is a schematic diagram for analyzing water saturation of a gas trap provided in an embodiment of the present application. As shown in fig. 9, the computer device can calculate the change of the water saturation of the gas trap with time by using the above method, so that a schematic diagram of the analysis of the water saturation of the gas trap can be obtained. The grid in the figure forms the bottom surface containing the balloon. FIG. 9 is a graph showing the distribution of water saturation with air traps.
Illustratively, fig. 10 is a schematic diagram of analyzing a pressure of a gas containing a trap provided in an embodiment of the present application. As shown in fig. 10, the computer device can calculate the change of the gas pressure containing the trap with time by using the method, so that a schematic diagram of the analysis of the gas pressure containing the trap can be obtained. The grid in the figure forms the bottom surface containing the balloon. Fig. 10 can reflect the distribution of the gas pressure including the trap.
As can be seen from fig. 8, 9, and 10, the saturation of the gas containing trap gradually increases and the saturation of the water gradually decreases from the outer well to the inner well. And the gas pressure is also gradually reduced, thereby forming a significant pressure drop funnel. That is, when natural gas is collected in the high part of a structure containing gas traps, the bottom hole pressure of a well is rapidly reduced, the well is flooded, and the yield of the well is reduced. It is therefore desirable to drill a target pattern from a formation low location to a formation high location and to harvest natural gas in the order from the formation low location to the formation high location. And determining the maximum distance of natural gas propagation in the gas-containing trap according to the gas saturation, the water saturation and the gas pressure of the gas-containing trap, wherein the distance is a target distance.
Optionally, the water-gas reservoir comprises at least two gas-containing traps. At the moment, the computer equipment controls the drilling equipment to drill according to the sequence from the low-position gas containing trap to the high-position gas containing trap to obtain a target well pattern corresponding to each gas containing trap in the at least two gas containing traps. Wherein the top of the low level gas containing trap is lower than the top of the high level gas containing trap.
Optionally, the computer device controls the drilling device to acquire natural gas according to the drilled circle of well after each circle of well is drilled in the gas containing trap. And finally, after a central well is drilled, collecting natural gas according to the central well.
Illustratively, with continued reference to fig. 6, in the gas containing trap 60, the computer device controls the drilling device to drill first to obtain the 1 st well 601, and controls the gas production device to produce natural gas through the 1 st well 601. Thereafter, a 2 nd well 602 is drilled and natural gas is collected through the 2 nd well 602. Then, a 3 rd circle of well 603 is drilled, and natural gas is collected through the 3 rd circle of well 603. Finally, a central well 604 is drilled and natural gas is collected through the central well 604.
In summary, the natural gas mining method provided by the embodiment of the application drills according to the sequence from the low-structure part to the high-structure part to obtain the target well pattern, and natural gas is collected through the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
In addition, the natural gas is drilled into the target well pattern according to the maximum natural gas propagation distance, each well in the target well pattern can be guaranteed to continuously collect the natural gas, and the efficiency of collecting the natural gas is improved. When the water gas reservoir comprises at least two gas-containing traps, the target well pattern is drilled according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap, so that the influence on the collection of the natural gas in other gas-containing traps when the natural gas in one gas-containing trap is collected can be reduced. The target distance is determined through the continuous seepage function of the gas-water two phases containing the gas trap, and a mode for determining the target distance more accurately is provided.
It should be noted that, the order of the steps of the method provided in the embodiments of the present application may be appropriately adjusted, and the steps may also be increased or decreased according to the circumstances, and any method that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall be covered by the protection scope of the present application, and therefore, the detailed description thereof is omitted.
Fig. 11 is a schematic structural diagram of a natural gas production system according to an embodiment of the present application. As shown in fig. 11, the system 110 includes:
and drilling equipment 1101 for drilling in the gas-containing trap with the water-gas reservoir in the order from the low part of the structure to the high part of the structure to obtain the target well pattern. The target pattern includes a centerwell and at least two rings of wells distributed around the centerwell. The well heads of the wells belonging to different rings and the central well in at least two rings of wells are different in height. The height of the wellhead is the height of the wellhead relative to the bottom of the gas-containing trap.
And the gas production equipment 1102 is used for collecting natural gas through the target well pattern.
Optionally, the system 110 may further comprise computer equipment for controlling the drilling equipment 1101 and the gas production equipment 1102.
In summary, the natural gas production system provided in the embodiment of the present application drills through the drilling equipment according to the sequence from the low structure position to the high structure position to obtain the target well pattern, and collects natural gas through the gas production equipment according to the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
Optionally, the target well pattern comprises wells having progressively increasing well head heights in a nested order from outside to inside in horizontal cross-section.
Optionally, a drilling apparatus 1101 for:
and (5) drilling for the ith time on the gas-containing trap to obtain an ith round of well.
And (5) drilling for the (i + 1) th time on the gas-containing trap to obtain an (i + 1) th circle of well. And the ith circle of wells are positioned at the periphery of the (i + 1) th circle of wells, and the distance between the well mouth of any well and the circle of the (i + 1) th circle of wells is the target distance along the direction of the connecting line of the well mouth of any well in the ith circle of wells and the top of the gas containing trap.
Wherein i is more than or equal to 1 and less than or equal to n-1, and n is the number of turns of at least two turns of wells. And for any circle of wells in at least two circles, the linear distance of the well mouths of m pairs of wells is the target distance, the linear distance of the well mouths of the rest pairs of wells is smaller than or equal to the target distance, and each pair of wells is two adjacent wells in any circle of wells.
Optionally, the wellhead of the 1 st well is located at the lowest part of the gas trap-containing structure, and the wellheads of the 1 st well are arranged along the edge of the bottom of the gas trap.
Optionally, as shown in fig. 12, the system 110 further includes:
the computer device 1103 is configured to determine a target distance according to a continuous seepage function of gas-water two phases containing the gas trap, where the function is configured to reflect seepage characteristics between water and natural gas in the gas trap.
Optionally, a computer device 1103 for:
determining the gas saturation, the water saturation and the gas pressure of the gas trap according to the function.
And determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as a target distance.
Optionally, the wellhead of the centerwell is located at the top of the gas containing trap.
Optionally, the water-gas reservoir comprises at least two gas-containing traps, drilling apparatus 1101 for:
and drilling according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap to obtain a target well pattern corresponding to each gas-containing trap in the at least two gas-containing traps.
Optionally, a drilling apparatus 1101 for:
after drilling to obtain at least two circles of wells, the central well is drilled.
In summary, the natural gas production system provided in the embodiment of the present application drills through the drilling equipment according to the sequence from the low structure position to the high structure position to obtain the target well pattern, and collects natural gas through the gas production equipment according to the target well pattern. Because the natural gas gathered at the low-structure part is less than the natural gas gathered at the high-structure part, the speed of pressure reduction at the bottom of the well can be reduced when the target well pattern is drilled and the natural gas is collected according to the sequence from the low-structure part to the high-structure part, so that the possibility that the well is flooded by water is reduced, and the efficiency of collecting the natural gas is improved.
In addition, the target well pattern is drilled according to the maximum distance of natural gas propagation, each well in the target well pattern can be guaranteed to continuously collect natural gas, and the efficiency of collecting the natural gas is improved. When the water gas reservoir comprises at least two gas-containing traps, the target well pattern is drilled according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap, so that the influence on the collection of the natural gas in other gas-containing traps when the natural gas in one gas-containing trap is collected can be reduced. The target distance is determined through the continuous seepage function of the gas-water two phases containing the gas trap, and a mode for determining the target distance more accurately is provided.
It should be noted that: the natural gas production system provided by the above embodiment is only exemplified by the division of the above devices, and in practical applications, the internal structure of the device may be divided into different sub-devices to achieve all or part of the above-described results. In addition, the natural gas exploitation system provided by the above embodiment and the natural gas exploitation method embodiment belong to the same concept, and specific implementation processes thereof are detailed in the method embodiment and are not described herein again.
The above description is only an example of the present application and should not be taken as limiting, and any modifications, equivalent switches, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (6)
1. A method of natural gas production, the method comprising:
determining the gas saturation, the water saturation and the gas pressure of the gas-containing trap according to a continuous seepage function of gas-water two phases of the gas-containing trap of the water-gas reservoir, wherein the continuous seepage function of the gas-water two phases is used for reflecting the seepage characteristics between water and natural gas in the gas-containing trap, the continuous seepage function of the gas-water two phases comprises a matrix system function and a fracture system function, and the matrix system function satisfies the following conditions:
the fracture system function satisfies:
wherein, K m∞ As a substrate by KelvinRate, in units of 10 -3 μm 2 ，K rmg Is the relative permeability, p, of the gas in the matrix mg Is the density of the gas in the matrix, in kg/m 3 ，μ mg Is the viscosity of the gas in the matrix in mPa · s, b is the slip factor of the matrix rock in mPa,
is the average pressure of the gas, in MPa,
is the pressure gradient of the gas in the matrix in MPa/m, g is the acceleration of gravity in m/s2, D is the buried depth in m, lambda mg Is the starting pressure gradient of the gas in the matrix, in units of MPa/m, F g Is the flow of gas, and has the unit of m 3 ，q mg Is the gas quantity in the matrix system, and the unit is m 3 ，φ m Is the porosity of the matrix in units of f, S mg Is the saturation of the gas in the matrix in units of f, K m Permeability as a matrix in 10 -3 μm 2 ，K rmw Is the relative permeability of water in the matrix, p mw The density of water in the matrix is in kg/m 3 ，μ mw Is the viscosity of water in the matrix, in mPas,
is the pressure gradient of water in the matrix, the unit is MPa/m,
the overlying pressure gradient of the rock is a matrix system, and the unit is MPa/m and lambda mw Is the starting pressure gradient of water in the matrix, in units of MPa/m, F w Is the cross-flow of water in m 3 ，q mw The amount of water in the matrix system is m 3 ，S mw Is the water saturation in the matrix, with the unit f, B is the gas non-Darcy coefficient, dimensionless, K f0 Is the initial permeability of the fracture in units of10 -3 μm 2 ，p e -m Is the stress sensitivity coefficient and has the unit of f, K rfg Is the relative permeability of the gas in the fracture, p fg The density of the gas in the cracks is expressed in kg/m 3 ，μ fg The viscosity of the gas in the fracture is expressed in mPas,
is the pressure gradient of the gas in the fracture, with units of MPa/m, rho fg The density of the gas in the cracks is expressed in kg/m 3 G is the acceleration of gravity, the unit is m/s2,
for depth variation, the unit is m, λ fg The pressure gradient is initiated for the gas in the fracture in MPa/m, q fg Is the gas amount in a crack system, and the unit is m 3 ，φ f Porosity of the fracture system in units of f, S fg Is the gas saturation in the fracture system, and the unit is f and K rfw Is the relative permeability of water in the fracture, ρ fw The density of water in the cracks is expressed in kg/m 3 ，μ fw The viscosity of water in the fracture is expressed in mPas,
is the pressure gradient of water in the crack, and the unit is MPa/m,
is the overlying pressure gradient of rock in a fracture system, and has the unit of MPa/m and lambda fw Is the starting pressure gradient of water in the fracture, and has the unit of MPa/m and q fw The amount of water in the fracture system is m 3 ，S fw The water saturation in the fracture system is represented by f;
determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as a target distance;
in the gas-containing trap, drilling in the order of a formation low site to a formation high site by:
drilling the gas-containing trap for the ith time to obtain an ith trap; drilling for the (i + 1) th time on the gas-containing trap to obtain an (i + 1) th circle of well; wherein the ith circle of well is positioned at the periphery of the (i + 1) th circle of well, the distance between the well mouth of any well and the circle of the (i + 1) th circle of well is a target distance along the direction of the connecting line of the well mouth of any well in the ith circle of well and the top of the gas containing trap, the target well pattern comprises a center well and at least two circles of wells distributed around the center well, the heights of the well mouths of the wells belonging to different circles in the at least two circles of wells are different from each other, the height of the well mouth is the height of the well mouth relative to the bottom of the gas containing trap, the heights of the well mouths of the wells included in the target well pattern are gradually increased according to the nesting sequence from outside to inside in the horizontal section, i is more than or equal to 1 and less than or equal to n-1, n is the number of circles of the at least two circles of wells, and the linear distance between m and the well mouths of the wells in any circle of the at least two circles of wells is the target distance, the linear distance between the well heads of the remaining pair of wells is smaller than or equal to the target distance, and each pair of wells is two adjacent wells in any circle of wells;
and collecting natural gas through the target well pattern.
2. The method of claim 1, wherein the wellhead of the 1 st well is located at the lowermost portion of the configuration of the gas-containing trap, and the wellhead of the 1 st well is arranged along the edge of the bottom of the gas-containing trap.
3. The method according to claim 1 or 2,
the well head of the central well is positioned at the top of the gas-containing trap.
4. The method of claim 1 or 2, wherein the water-gas reservoir comprises at least two gas-containing traps, the method further comprising:
and drilling according to the sequence from the low-position gas-containing trap to the high-position gas-containing trap to obtain the target well pattern corresponding to each gas-containing trap in the at least two gas-containing traps.
5. The method according to claim 1 or 2, characterized in that the method further comprises:
drilling the central well after drilling the at least two rings of wells.
6. A natural gas production system, the system comprising:
computer equipment for determining the gas saturation, the water saturation and the gas pressure of the gas-containing trap according to a continuous seepage function of gas-water two phases of the gas-containing trap with a water-gas reservoir, wherein the continuous seepage function of the gas-water two phases is used for reflecting the seepage characteristics between water and natural gas in the gas-containing trap, the continuous seepage function of the gas-water two phases comprises a matrix system function and a fracture system function, and the matrix system function satisfies the following conditions:
the fracture system function satisfies:
wherein, K m∞ The Kjeldahl permeability of the matrix is 10 -3 μm 2 ，K rmg Is the relative permeability of the gas in the matrix, p mg Is the density of the gas in the matrix, in kg/m 3 ，μ mg Is the viscosity of the gas in the matrix in mPa · s, b is the slip factor of the matrix rock in mPa,
is the average pressure of the gas, in MPa,
is the pressure gradient of the gas in the matrix in MPa/m, g is the acceleration of gravity in m/s2, D is the buried depth in m, lambda mg Is the starting pressure gradient of the gas in the matrix, with units of MPa/m, F g Is the flow of gas, and has the unit of m 3 ，q mg Is the gas quantity in the matrix system, and the unit is m 3 ，φ m Is the porosity of the matrix in units of f, S mg Is the saturation of the gas in the matrix in units of f, K m Permeability of the matrix in units of 10 -3 μm 2 ，K rmw Is the relative permeability of water in the matrix, p mw The density of water in the matrix is in kg/m 3 ，μ mw Is the viscosity of water in the matrix, in mPas,
is the pressure gradient of water in the matrix, the unit is MPa/m,
the overlying pressure gradient of the rock is a matrix system, and the unit is MPa/m and lambda mw Is the starting pressure gradient of water in the matrix, with units of MPa/m, F w Is the flow cross-over of water in m 3 ，q mw The amount of water in the matrix system is m 3 ，S mw Is the water saturation in the matrix, with the unit f, B is the gas non-Darcy coefficient, dimensionless, K f0 The initial permeability of the fracture is given in units of 10 -3 μm 2 ，p e -m Is the stress sensitivity coefficient and has the unit of f, K rfg Is the relative permeability of the gas in the fracture, p fg The density of the gas in the cracks is expressed in kg/m 3 ，μ fg The viscosity of the gas in the fracture is expressed in mPas,
is the pressure gradient of the gas in the fracture, with units of MPa/m, rho fg The density of the gas in the cracks is expressed in kg/m 3 G is the acceleration of gravity, the unit is m/s2,
the unit is m, lambda for the depth variation fg The pressure gradient is initiated by gas in the crack, and the unit is MPa/m and q fg Is the gas quantity in the crack system, and the unit is m 3 ，φ f Porosity of the fracture system in units of f, S fg Is the gas saturation in the fracture system and has the unit of f, K rfw Is the relative permeability of water in the fracture, ρ fw The density of water in the cracks is expressed in kg/m 3 ，μ fw The viscosity of water in the fracture is expressed in mPas,
is the pressure gradient of water in the crack, and the unit is MPa/m,
the unit of the overlying pressure gradient of the rock in the fracture system is MPa/m and lambda fw Is the starting pressure gradient of water in the fracture, and has the unit of MPa/m and q fw The amount of water in the fracture system is m 3 ，S fw The water saturation in the fracture system is represented by f; determining the maximum distance of natural gas propagation according to the gas saturation, the water saturation and the gas pressure, and taking the maximum distance of natural gas propagation as a target distance;
drilling equipment for drilling in the gas-containing trap in the order of formation low to formation high to obtain a target well pattern by:
drilling the gas-containing trap for the ith time to obtain an ith trap; drilling for the (i + 1) th time on the gas-containing trap to obtain an (i + 1) th circle of well; wherein, the ith circle of well is positioned at the periphery of the (i + 1) th circle of well, the distance between the well mouth of any well and the circle of the (i + 1) th circle of well is a target distance along the direction of the connecting line between the well mouth of any well in the ith circle of well and the top of the gas containing trap, the target well pattern comprises a center well and at least two circles of wells distributed around the center well, the heights of the well mouths of the wells belonging to different circles in the at least two circles of wells are different from each other, the height of the well mouth is the height of the well mouth relative to the bottom of the gas containing trap, the heights of the well mouths of the wells included in the target well pattern are gradually increased according to the nesting sequence from outside to inside in the horizontal section, i is more than or equal to 1 and less than or equal to n-1, n is the number of circles of the at least two circles of wells, and the linear distance between m and the well mouths of the wells in any circle of the at least two circles of wells is the target distance, the linear distance between the well heads of the rest pair of wells is less than or equal to the target distance, and each pair of wells is two adjacent wells in any circle of wells;
and the gas production equipment is used for collecting natural gas through the target well pattern.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011123648.XA CN112253052B (en) | 2020-10-20 | 2020-10-20 | Natural gas exploitation method and natural gas exploitation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011123648.XA CN112253052B (en) | 2020-10-20 | 2020-10-20 | Natural gas exploitation method and natural gas exploitation system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112253052A CN112253052A (en) | 2021-01-22 |
| CN112253052B true CN112253052B (en) | 2022-08-30 |
Family
ID=74244338
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011123648.XA Active CN112253052B (en) | 2020-10-20 | 2020-10-20 | Natural gas exploitation method and natural gas exploitation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112253052B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2554971C1 (en) * | 2014-08-25 | 2015-07-10 | Открытое акционерное общество "Татнефть" им. В.Д.Шашина | Method of oil field development |
| CN108412467A (en) * | 2018-02-23 | 2018-08-17 | 中国石油大学(北京) | A kind of the well pattern mining system and recovery method of gas hydrates |
| RU2704688C1 (en) * | 2019-03-01 | 2019-10-30 | Публичное акционерное общество "Татнефть" им. В.Д.Шашина | Method for development of structural oil deposit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016043980A1 (en) * | 2014-09-18 | 2016-03-24 | Exxonmobil Upstream Research Company | Method to perform hydrocarbon system analysis for exploration, production and development of hydrocarbons |
-
2020
- 2020-10-20 CN CN202011123648.XA patent/CN112253052B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2554971C1 (en) * | 2014-08-25 | 2015-07-10 | Открытое акционерное общество "Татнефть" им. В.Д.Шашина | Method of oil field development |
| CN108412467A (en) * | 2018-02-23 | 2018-08-17 | 中国石油大学(北京) | A kind of the well pattern mining system and recovery method of gas hydrates |
| RU2704688C1 (en) * | 2019-03-01 | 2019-10-30 | Публичное акционерное общество "Татнефть" им. В.Д.Шашина | Method for development of structural oil deposit |
Non-Patent Citations (1)
| Title |
|---|
| 一种边水气藏水侵方向定量识别方法――以川东地区黄龙场长兴组生物礁气藏为例;徐昌海等;《天然气勘探与开发》;20191231;第42卷(第04期);第90-96页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112253052A (en) | 2021-01-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wardlaw et al. | Mercury porosimetry and the interpretation of pore geometry in sedimentary rocks and artificial models | |
| McGee et al. | Geologic models and reservoir geometries of Auger Field, deepwater Gulf of Mexico | |
| CN107701180A (en) | A kind of the original reservoir water saturation computational methods based on sealing core drilling | |
| Klimchouk et al. | Karst breakdown mechanisms from observations in the gypsum caves of the Western Ukraine: implications for subsidence hazard assessment | |
| CN105442520A (en) | Deformation and stability monitoring system for side slope and whole process of construction period and primary water storage period of dam | |
| CN115408886B (en) | Water lowering and draining system and method for controlling underground structure settlement through hydraulic engineering | |
| CN112253052B (en) | Natural gas exploitation method and natural gas exploitation system | |
| US20140278318A1 (en) | Natural Resource Reservoir Modeling | |
| Purdy et al. | Reservoir implications of modern karst topography | |
| KR20170121482A (en) | Ground Water Movement Measurement Method for Estuary Region | |
| CN110991933A (en) | Mountain shale gas resource evaluation method and system | |
| CN104655191B (en) | Multi-parameter and three-dimensional monitoring method and monitoring probe for reservoir bank of water-level-fluctuating zone | |
| CN107339096A (en) | A kind of quick groundwater prospecting method of horizontal well | |
| Ward et al. | Differential compaction over Late Miocene submarine channels in SE Brazil: Implications for trap formation | |
| CN110244356B (en) | Identification method for later-period oil and gas reservoir formed by structural damage | |
| Eckles et al. | Late Quaternary evolution of the wave–storm-dominated central Texas shelf | |
| CN109868833A (en) | The control method of binary structural stratum deep foundation pit precipitation amount | |
| CN110232245A (en) | Suspended cutoff Foundation Pit with Confined Water pumping with constant rate three-dimensional flow field water level distribution determination method | |
| CN107327291B (en) | A kind of method of the best pattern of determining carbon dioxide phase transformation fracturing coal seam anatonosis | |
| CN112505759B (en) | Prediction method for gas saturation distribution of low-permeability sandstone reservoir | |
| Wu et al. | Controlling effects of the Ordovician carbonate pore structure on hydrocarbon reservoirs in the Tarim Basin, China | |
| CN110244357A (en) | A kind of structure destruction type Foregone pool sentences knowledge method | |
| Bryant et al. | Statistical relationships between geotechnical properties of Gulf of Mexico sediments | |
| CN112814643B (en) | Well spacing method for shale oil and gas reservoir sweet spot area | |
| CN114109372B (en) | Method, device, equipment and storage medium for determining perforation positions of oil and gas wells |
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 |