Early warning method and device for water invasion time of high-pressure gas well

Abstract

The invention discloses a high-pressure gas well water invasion time early warning method and device. The method comprises the steps that according to historical production data of a gas well, the flowing bottomhole pressure and the gas production rate corresponding to each production time are determined and put into a coordinate system with the flowing bottomhole pressure and the gas production rate as coordinate axes, the path direction of the midpoint of the coordinate system is determined according to the time sequence, and a time point sequence is obtained; dividing the coordinate system into four quadrants according to the position of the highest point of the gas production rate; in the time point sequence, a first point falling in a selected quadrant is searched from the highest point of the gas production rate according to the sequence from front to back, the production time corresponding to the first point is determined as the water invasion starting time, and the selected quadrant is the quadrant with the minimum flowing bottomhole pressure and the minimum gas production rate in the four quadrants. According to the method, the water invasion can be predicted before the wellhead water breakthrough is monitored according to limited historical production data, and the recovery efficiency of the water-driven gas reservoir is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of deep-layer natural gas development, and in particular to a high-pressure gas well water intrusion time early warning method and device. Background Art

[0002] The difficulty of natural gas development lies in the impact of water invasion. Its special feature is that it is difficult to predict the occurrence of water invasion and the amount of water invasion is difficult to determine. When the pressure wave reaches the boundary, the water body in the periphery will inevitably invade the gas reservoir. Accurately predicting the time of water invasion has extremely high industrial value for improving the recovery rate of water-driven gas reservoir development in the later stage. Therefore, water invasion warning is a very valuable technology for natural gas development and a key technology to achieve a higher recovery rate of water-driven gas reservoirs.

[0003] As early as the 1930s, foreign countries had relatively mature theories of water-driven gas reservoir development, which were developed based on the material balance theory of gas reservoirs. In the existing technology, the water invasion of gas reservoirs is determined based on formation pressure testing, mainly in the following ways:

[0004] (1) Difference method

[0005] The difference method was proposed by Li Chuanliang. It mainly ignores the water intrusion of the gas reservoir in the initial stage of gas reservoir development, regards it as a constant volume gas reservoir, and makes a production indicator curve. Then, it is subtracted from the actual water gas reservoir production indicator curve, and the water intrusion value is obtained using the water storage coefficient. The specific method is as follows:

[0006] For a gas reservoir with water, the material balance equation is:

[0007]

[0008] In the formula, is the gas reservoir volume compression coefficient, MPa -1 ,s wc —Immobile water saturation, c w —Compressibility of water, MPa -1 , c p —Compression coefficient of rock, MPa -1 ; is the water volume coefficient, that is, the percentage of water volume to gas reservoir volume, We—the cumulative water intrusion of gas reservoir, ten thousand cubic meters, Wp—the cumulative water production of gas reservoir, ten thousand cubic meters, B w —Volume coefficient of water, A g —Gas-bearing area of ​​gas reservoir, km 2 , h—effective reservoir thickness, m, Φ—reservoir porosity, decimal; P—formation pressure, MPa; Z—natural gas deviation factor; G—gas reservoir reserves, ten thousand cubic meters; G p —Cumulative gas production, ten thousand cubic meters; i—indicates the initial state; ΔP—change in formation pressure.

[0009] The pseudo pressure P p If it is expressed as:

[0010]

[0011] Let P H =P p (1-c c ΔP-w), the above formula becomes:

[0012]

[0013] Among them, P H is the H pressure of the gas reservoir, MPa; P Hi is the H pressure of the gas reservoir under original conditions, P Hi =P pi =P i / Z i , MPa.

[0014] Since the water invasion amount of water-bearing gas reservoirs is unknown, it is impossible to draw a production indicator curve. However, the water invasion amount is very small and negligible in the early stage of water-bearing gas reservoir development. The gas reservoir can be regarded as a constant volume gas reservoir, and its material balance equation is:

[0015]

[0016] That is:

[0017]

[0018] In the early stage of mining, P F ~G p Curve and P H ~G p The curves are almost overlapped, and the initial stage P F ~G p The curve is extended to obtain P H ~G p Curve. As the mining time increases, the water invasion becomes more serious, the amount of water invasion increases and cannot be ignored, P F ~G p The curve will bend away from P H ~G p Curve, see Figure 1 The difference between the two lines can be used to determine the water intrusion value.

[0019] The two-line difference calculation formula is as follows:

[0020]

[0021] According to the difference, the water storage volume coefficient can be calculated, and then the water intrusion value can be solved:

[0022] W e =W p B w +W=W p B w +V ci w=W p B w +GB gi ΔP F Z / P (1-7)

[0023] Among them, geological reserves G can be calculated from P H ~G p The curve is calculated.

[0024] Although this method is simple to calculate, it must have continuous monitoring data of formation pressure, and it is often difficult for monitoring data to deviate from the straight line segment. Therefore, this method is only suitable for homogeneous gas reservoirs with weak water invasion in the initial stage of exploitation and negligible water invasion. For fracture-pore gas reservoirs, since their flow channels are fractures and their permeability is much greater than that of homogeneous formation fluid flow channels, water invasion occurs in advance (which can also be reflected according to the dimensionless water invasion chart), and the water invasion in the initial stage cannot be ignored.

[0025] (2) Plate method

[0026] The graphic method was proposed by Li Chuanliang. First, let the dimensionless pressure P pD is the ratio of the pseudo-pressure of the gas reservoir to the pseudo-pressure of the gas reservoir under the original conditions:

[0027]

[0028] Substitute it into the material balance equation of the gas reservoir and set m = c c ΔP+w, after being dimensionless, becomes:

[0029]

[0030] in, It is the recovery degree, which is the ratio of the cumulative production to the geological reserves of the gas reservoir, a decimal.

[0031] According to the material balance equation obtained by dimensionless transformation, a graph of m value is made. For specific graphs, see Figure 2 shown.

[0032] Compare the production data with the chart, first determine the time of deviation from the diagonal line, that is, the water invasion time, then determine the m value of the gas reservoir, and then calculate the water invasion value. The calculation formula is as follows:

[0033] W e =W p B w +GBgi (mc c ΔP) (2-3)

[0034] The premise of using this method is to determine the geological reserves G of the gas reservoir or single well. For homogeneous gas reservoirs, in the early stage of exploitation, P F ~G p Curve and P H ~G p The curves are almost overlapped, and the initial stage P F ~G p The curve is extended to obtain P H ~G p By extending P H ~G p Curve, find the intersection with the x-axis, determine the geological reserves of the gas reservoir, and thus obtain its water invasion value.

[0035] (3) Geological reserve method

[0036] Transform the previous material balance equation and convert the deviation factor of natural gas into volume coefficient, then the material balance equation of water gas reservoir is:

[0037] G p B g +W p B w =G(B g -B gi )+GB gi c c ΔP+W e (3-1)

[0038] And then sorted into:

[0039]

[0040] Apparent geological reserves G a for:

[0041]

[0042] Then the material balance equation becomes:

[0043]

[0044] It can be seen from the above formula that in the early stage of production, the water intrusion is close to 0, G p Approaching 0, considering the geological reserves G a By drawing a curve of apparent geological reserves, see Figure 3 shown.

[0045] According to the above curve, the water invasion time is determined according to the deviation of the curve from the straight line, and the water invasion value of the gas reservoir is determined according to the deviation difference. Summary of the invention

[0046] The inventors found that the above methods all use sufficient monitoring data and can only accurately calculate the amount of water intrusion under the condition of a long production history, but cannot predict the time of water intrusion in advance. Therefore, there is an urgent need for a water intrusion early warning technology for high-pressure gas wells with limited data.

[0047] In order to at least partially solve the technical problems existing in the prior art, the inventors have made the present invention, and through a specific implementation method, provide a high-pressure gas well water intrusion time early warning method and device, which can predict water intrusion before monitoring water at the wellhead based on limited historical production data, thereby effectively improving the recovery efficiency of water-driven gas reservoirs.

[0048] In a first aspect, an embodiment of the present invention provides a high-pressure gas well water intrusion time early warning method, comprising:

[0049] According to the historical production data of the gas well, the bottom hole pressure and gas production corresponding to each production time are determined, and then projected into a coordinate system with the bottom hole pressure and gas production as the coordinate axes. The path direction of the midpoint of the coordinate system is determined in time sequence to obtain a time point sequence;

[0050] The coordinate system is divided into four quadrants according to the position of the highest gas production point;

[0051] In the time point sequence, starting from the highest gas production point, the first point falling in the selected quadrant is found in order from front to back, and the production time corresponding to the point is determined as the water invasion start time. The selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants.

[0052] In a second aspect, an embodiment of the present invention provides a high-pressure gas well water intrusion time early warning device, comprising:

[0053] The time point sequence acquisition module is used to determine the bottom hole flow pressure and gas production corresponding to each production time according to the historical production data of the gas well, and project them into a coordinate system with the bottom hole flow pressure and gas production as the coordinate axes, determine the path direction of the midpoint of the coordinate system in time sequence, and obtain the time point sequence;

[0054] A quadrant division module, used for dividing the coordinate system into four quadrants according to the position of the highest gas production point;

[0055] The water invasion start time prediction module is used to find the first point that falls in the selected quadrant in the time point sequence, starting from the highest gas production point, in a forward-to-back order, and determine the production time corresponding to the point as the water invasion start time. The selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants.

[0056] In a third aspect, an embodiment of the present invention provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned high-pressure gas well water intrusion time warning method is implemented.

[0057] In a fourth aspect, an embodiment of the present disclosure provides a server, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned high-pressure gas well water intrusion time warning method when executing the program.

[0058] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0059] (1) The prior art determines whether water invasion has occurred based on the water-gas ratio of the output fluid. First, it is impossible to monitor the water-gas ratio of the output fluid of the gas well in real time; second, there is a certain time difference between the occurrence of groundwater invasion and the increase of water and gas in the output fluid. Therefore, there is a certain lag in determining the water invasion time by the water-gas ratio of the output fluid. The high-pressure gas well water invasion time early warning method provided by the embodiment of the present invention first draws a time point sequence of bottom hole flow pressure and gas production; then divides four quadrants according to the position of the highest gas production point, and selects the quadrant with the lowest bottom hole flow pressure and gas production; in the time point sequence, starting from the highest gas production point, in order from front to back, find the first point that falls in the selected quadrant, and determine the production time corresponding to the point as the start time of water invasion. It can predict water invasion before monitoring water at the wellhead based on limited historical production data, and can take corresponding water control measures in time to effectively improve the recovery efficiency of water-driven gas reservoirs.

[0060] (2) The high-pressure gas well water intrusion time warning method provided by the embodiment of the present invention only requires bottom hole flow pressure data and gas production data, which overcomes the disadvantage that the previous water intrusion identification method must have a large number of formation pressure tests. Water intrusion identification is performed according to the gas reservoir material balance method, and the method is simple and has high prediction accuracy.

[0061] (3) Due to changes in the work system and other reasons, the time of water invasion may be earlier than the time of the highest gas production point. The high-pressure gas well water invasion time warning method provided by the embodiment of the present invention traverses the points in the time point sequence in order from front to back, and determines the ratio of the number of points in the currently traversed points that fall within the selected quadrant to the total number of points in the coordinate system. If the currently determined ratio is smaller than the previous ratio, the production time corresponding to the previous point of the currently traversed point is determined as the probabilistic water invasion time; if the probabilistic water invasion time is earlier than the determined water invasion start time, the water invasion start time is corrected to the probabilistic water invasion time. The rationality and timeliness of the determined water invasion start time are ensured.

[0062] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0063] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0065] Figure 1 P is the P of the water-containing gas reservoir used in the prior art to calculate water invasion F Schematic diagram of pressure curve;

[0066] Figure 2 A schematic diagram of a gas reservoir water invasion calculation chart used in the prior art to calculate water invasion;

[0067] Figure 3 A schematic diagram of a gas reservoir apparent geological reserve change curve used in the prior art to calculate water intrusion;

[0068] Figure 4 Flow chart of a method for early warning of water intrusion time in a high-pressure gas well in an embodiment of the present invention;

[0069] Figure 5 A schematic diagram of a time point sequence and quadrant division in an embodiment of the present invention;

[0070] Figure 6 Schematic diagram of the water invasion point determined by the maximum gas production of Well xx-11 and the water invasion point determined by probability in an embodiment of the present invention;

[0071] Figure 7 Schematic diagram of the water invasion point determined by the maximum gas production of Well xx-12 and the water invasion point determined by probability in an embodiment of the present invention;

[0072] Figure 8 Schematic diagram of the structure of a high-pressure gas well water intrusion time early warning device in an embodiment of the present invention. DETAILED DESCRIPTION

[0073] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0074] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0075] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0076] Taking the square of pressure as an example, the principle of the high-pressure gas well water invasion time early warning method and device provided by the present application is explained below. When the gas well production is:

[0077]

[0078] In formula (1): q sc —Gas production, 10 4 m 3 / d; k—reservoir permeability, μm 2 ; —Average formation pressure, MPa; p wf — Bottom hole flowing pressure, MPa; —Natural gas deviation factor, dimensionless; —Natural gas viscosity, mPa.s; r e —Gas supply radius of a single well, m; r w—well radius, m; S—contamination coefficient, dimensionless; h—effective reservoir thickness, m; T—reservoir temperature.

[0079] From formula (1), we know that when the output q sc When it reaches the highest point, it means reaches the maximum, at which point the flow pressure is determined, only when the formation pressure is the original formation pressure, that is, Maximum, when the formation pressure decreases, Then we have:

[0080]

[0081] At this time, there must be:

[0082]

[0083] It can be seen from this that the output will inevitably decrease. Figure 5 As shown in the figure, a horizontal line and a vertical line are drawn through the highest point of gas production. The formation pressure corresponding to the data points falling in quadrant III (lower left quadrant) begins to decrease. If the formation pressure does not decrease, the flow pressure p of the points in quadrant III is wf3 <Flow pressure at the highest production point p wfmax , then:

[0084]

[0085] Then we have:

[0086] q sc3 >q scmax (5)

[0087] Obviously (5) is inconsistent with the actual production data. Therefore, the data entering the third quadrant is at the stage where the formation pressure begins to decrease. If there is edge water or bottom water in the gas reservoir, water invasion will occur during development. The time corresponding to the first data point entering the third quadrant is the time when water invasion occurs. First find the production date corresponding to the highest production point, and then find the first point in the third quadrant from this date and stop searching.

[0088] Embodiment 1

[0089] Embodiment 1 of the present invention provides a high-pressure gas well water invasion time early warning method, the process of which is as follows Figure 4 As shown, the following steps are included:

[0090] Step S41: According to the historical production data of the gas well, determine the bottom hole pressure and gas production corresponding to each production time, and project them into a coordinate system with the bottom hole pressure and gas production as coordinate axes, determine the path direction of the midpoint of the coordinate system in time sequence, and obtain a time point sequence.

[0091] The historical production data directly obtained may not contain bottomhole flow pressure, but wellhead oil pressure or casing pressure. The wellhead oil pressure or casing pressure corresponding to each production time in the historical production data of the gas well can be converted into bottomhole flow pressure to obtain the bottomhole flow pressure and gas production corresponding to each production time.

[0092] The bottom hole pressure can be used as the vertical coordinate, the gas production can be used as the horizontal coordinate, the gas production can be used as the daily gas production, and the production time can be used as the production day. Figure 5 If the production time is the production day, the predicted water intrusion time can be accurate to the day.

[0093] The bottom hole flow pressure and gas production corresponding to each production time are projected into the coordinate system to obtain a point, and the path direction of the point in the coordinate system is determined in time sequence to obtain a time point sequence.

[0094] Step S42: Divide the coordinate system into four quadrants according to the position of the highest gas production point.

[0095] Draw horizontal and vertical lines through the highest point of gas production to divide the coordinate system into four quadrants, among which the quadrant with the lowest bottom hole pressure and gas production is Figure 5 The lower left quadrant shown in the figure is quadrant III, which is also the quadrant of greatest concern in this application; the upper left quadrant (the quadrant with the largest bottom hole pressure and the smallest gas production) is quadrant IV.

[0096] All points fall in either Quadrant III or Quadrant IV.

[0097] Step S43: In the time point sequence, starting from the highest gas production point, in order from front to back, find the first point that falls in the selected quadrant, and determine the production time corresponding to the point as the water intrusion start time.

[0098] Among them, the selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants, that is, the above-mentioned quadrant III.

[0099] The existing technology is to judge whether water invasion has occurred based on the water-gas ratio of the produced fluid. First, it is impossible to monitor the water-gas ratio of the produced fluid of the gas well in real time; second, there is a certain time difference between the occurrence of groundwater invasion and the increase of water and gas in the produced fluid. Therefore, there is usually a certain lag in determining the water invasion time by the water-gas ratio of the produced fluid. The high-pressure gas well water invasion time early warning method provided in Example 1 of the present invention first draws a time point sequence of bottom hole flow pressure and gas production; then divides four quadrants according to the position of the highest gas production point, and selects the quadrant with the lowest bottom hole flow pressure and gas production; in the time point sequence, starting from the highest gas production point, in order from front to back, find the first point that falls in the selected quadrant, and determine the production time corresponding to the point as the start time of water invasion. It can predict water invasion before monitoring water at the wellhead based on limited historical production data, and can take corresponding water control measures in time to effectively improve the recovery efficiency of water-driven gas reservoirs.

[0100] The high-pressure gas well water intrusion time warning method provided in Example 1 of the present invention only requires bottom hole flow pressure data and gas production data, which overcomes the disadvantage that previous water intrusion identification methods must have more formation pressure tests. Water intrusion identification is performed based on the gas reservoir material balance method, and the method is simple and has high prediction accuracy.

[0101] Once water invasion occurs in the gas reservoir, formation water continuously flows to the bottom of the well, causing the water-gas ratio of the production well to increase continuously, resulting in a decrease in gas production. The data points fall in quadrant III at most points. The time when water invasion occurs may be earlier than the time of the highest gas production point. Therefore, in some embodiments, it also includes:

[0102] Traverse the points in the time point sequence in order from front to back, and determine the ratio of the number of points in the currently traversed points that fall in the selected quadrant to the total number of points in the coordinate system. If the currently determined ratio is smaller than the previous ratio, the production time corresponding to the previous point of the currently traversed point is determined as the probabilistic water intrusion time; if the probabilistic water intrusion time is earlier than the determined water intrusion start time, the water intrusion start time is corrected to the probabilistic water intrusion time.

[0103] Furthermore, before correcting the water intrusion start time, it is also possible to determine whether the water vapor ratio corresponding to the probabilistic water intrusion time is greater than a set water vapor ratio threshold. If so, the water intrusion start time is corrected to the probabilistic water intrusion time.

[0104] The water-gas ratio threshold can be set to 1 cubic meter per 10,000 cubic meters. Generally, a water-gas ratio > 1 cubic meter per 10,000 cubic meters indicates that the water mainly comes from the edge and bottom water, and it can be determined that water intrusion has occurred; otherwise, it indicates that the water comes from the movable water between the layers or the sealing layer.

[0105] Generally, the time of maximum gas production is close to the time of probabilistic water invasion, because the production starts to decline only when the energy of the formation is exhausted. However, there are some differences sometimes, which are mainly caused by changes in the working system, such as Figure 6As shown in Figure 2, for Well XX-11, the water invasion point determined by the highest gas production is very close to the point determined by probability. Figure 7 As shown in the figure, for Well xx-12, the water invasion point determined by the highest gas production is quite different from the point determined by probability. At this time, whether water invasion occurs can be further determined based on the water-gas ratio.

[0106] Due to changes in the working system and other reasons, the time when water invasion occurs may be earlier than the time of the highest gas production point. The high-pressure gas well water invasion time early warning method provided by the embodiment of the present invention corrects the water invasion start time according to the probabilistic water invasion time, thereby ensuring the rationality and timeliness of the determined water invasion start time.

[0107] Embodiment 2

[0108] Embodiment 2 of the present invention provides a specific application of a high-pressure gas well water intrusion time early warning method.

[0109] The statistics of water invasion time in the xx well area are shown in Table 1. There are 25 wells in total, 14 of which have experienced water invasion, accounting for 56%. Wells with high water-gas ratios also experienced water invasion earlier, indicating that fractures in the xx2 well area are relatively developed and water is very easy to appear. The degree of consistency with actual production is very high. The initial time in Table 1 is the time corresponding to the highest gas production, the probability time is the probability water invasion time determined by the above method, and the water appearance time is the water appearance time obtained by monitoring the water-gas ratio.

[0110] Table 1xx2 Water intrusion occurrence time statistics in well area

[0111]

[0112] Based on the inventive concept of the present invention, the embodiment of the present invention also provides a high-pressure gas well water invasion time warning device, the structure of the device is as follows: Figure 8 As shown, including:

[0113] The time point sequence acquisition module 81 is used to determine the bottom hole flow pressure and gas production corresponding to each production time according to the historical production data of the gas well, and project them into a coordinate system with the bottom hole flow pressure and gas production as coordinate axes, determine the path direction of the midpoint of the coordinate system in time sequence, and obtain the time point sequence;

[0114] A quadrant division module 82, for dividing the coordinate system into four quadrants according to the position of the highest gas production point;

[0115] The water invasion start time prediction module 83 is used to find the first point that falls in the selected quadrant in the time point sequence, starting from the highest gas production point, in a forward-to-back order, and determine the production time corresponding to the point as the water invasion start time. The selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants.

[0116] In some embodiments, the apparatus further comprises a correction module 84, configured to:

[0117] The points in the time point sequence are traversed in order from front to back, and the ratio of the number of points in the currently traversed points that fall in the selected quadrant to the total number of points in the coordinate system is determined; if the currently determined ratio is smaller than the previous ratio, the production time corresponding to the previous point of the currently traversed point is determined as the probabilistic water intrusion time; if the probabilistic water intrusion time is earlier than the determined water intrusion start time, the water intrusion start time is corrected to the probabilistic water intrusion time.

[0118] In some embodiments, the correction module 84 corrects the water intrusion start time to be before the probable water intrusion time, and is further used to:

[0119] It is determined whether the water-gas ratio corresponding to the probabilistic water intrusion time is greater than a set water-gas ratio threshold value. If so, the water intrusion start time is corrected to the probabilistic water intrusion time.

[0120] In some embodiments, the time point sequence acquisition module 81 is used to:

[0121] The wellhead oil pressure or casing pressure corresponding to each production time in the historical production data of the gas well is converted into the bottom hole flowing pressure, and the bottom hole flowing pressure and gas production corresponding to each production time are obtained.

[0122] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0123] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned high-pressure gas well water invasion time warning method is implemented.

[0124] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned high-pressure gas well water intrusion time warning method when executing the program.

[0125] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0126] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0127] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that an embodiment of the claimed subject matter requires more features than those set forth in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0128] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0129] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0130] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0131] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A high-pressure gas well water intrusion time early warning method, characterized in that: include: According to the historical production data of the gas well, the bottom hole pressure and gas production corresponding to each production time are determined, and then projected into a coordinate system with the bottom hole pressure and gas production as the coordinate axes. The path direction of the midpoint of the coordinate system is determined in time sequence to obtain a time point sequence; The coordinate system is divided into four quadrants according to the position of the highest gas production point; In the time point sequence, starting from the highest gas production point, the first point falling in the selected quadrant is found in order from front to back, and the production time corresponding to the point is determined as the water invasion start time. The selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants.

2. The method according to claim 1, characterized in that Also includes: Traversing the points in the time point sequence in order from front to back, determining the ratio of the number of points in the currently traversed points that fall in the selected quadrant to the total number of points in the coordinate system, and if the currently determined ratio is smaller than the previous ratio, determining the production time corresponding to the previous point of the currently traversed point as the probabilistic water intrusion time; If the probabilistic water intrusion time is earlier than the determined water intrusion start time, the water intrusion start time is corrected to the probabilistic water intrusion time.

3. The method according to claim 2, characterized in that The step of correcting the water intrusion start time to before the probable water intrusion time further includes: It is determined whether the water-gas ratio corresponding to the probabilistic water intrusion time is greater than a set water-gas ratio threshold value. If so, the water intrusion start time is corrected to the probabilistic water intrusion time.

4. The method according to claim 3, characterized in that The water-gas ratio threshold is 1 / 10000.

5. The method according to any one of claims 1 to 4, characterized in that: Determining the bottom hole flow pressure and gas production corresponding to each production time based on the historical production data of the gas well includes: The wellhead oil pressure or casing pressure corresponding to each production time in the historical production data of the gas well is converted into the bottom hole flowing pressure, and the bottom hole flowing pressure and gas production corresponding to each production time are obtained.

6. The method according to any one of claims 1 to 4, characterized in that: The coordinate system uses the bottom hole flowing pressure as the ordinate and the gas production as the abscissa.

7. The method according to any one of claims 1 to 4, characterized in that: The gas production is daily gas production.

8. A high-pressure gas well water intrusion time warning device, characterized in that: The device comprises: The time point sequence acquisition module is used to determine the bottom hole flow pressure and gas production corresponding to each production time according to the historical production data of the gas well, and project them into a coordinate system with the bottom hole flow pressure and gas production as the coordinate axes, determine the path direction of the midpoint of the coordinate system in time sequence, and obtain the time point sequence; A quadrant division module, used for dividing the coordinate system into four quadrants according to the position of the highest gas production point; The water invasion start time prediction module is used to find the first point that falls in the selected quadrant in the time point sequence, starting from the highest gas production point, in a forward-to-back order, and determine the production time corresponding to the point as the water invasion start time. The selected quadrant is the quadrant with the smallest bottom hole flow pressure and gas production among the four quadrants.

9. A computer storage medium, characterized in that The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the high-pressure gas well water invasion time early warning method according to any one of claims 1 to 7 is implemented.

10. A server, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the high-pressure gas well water invasion time early warning method as claimed in any one of claims 1 to 7 is implemented.

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