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CN-122014194-A - Fracturing well single well production regulation and control method and system based on real-time diagnosis

CN122014194ACN 122014194 ACN122014194 ACN 122014194ACN-122014194-A

Abstract

The invention relates to a method and a system for regulating and controlling single well production of a fractured well based on real-time diagnosis, and aims to overcome the defects of strategy statics, diagnosis feedback lag, poor field data quality and the like in the prior art. The method comprises the steps of obtaining bottom hole flow pressure data and yield data of a target production well in real time, preprocessing the data, performing inversion calculation to obtain effective fracture surface area representing fracture conductivity, and automatically generating a regulating instruction for regulating the opening of a choke plug according to the real-time change trend of the effective fracture surface area. The method realizes continuous and reliable supply of key data under low cost through virtualized data acquisition and high-fidelity preprocessing, realizes online accurate perception of the crack health state through engineering a global transient analysis model into a real-time diagnosis core, finally forms a closed loop of perception-diagnosis-decision-control, realizes self-adaptive production regulation and control of a single well, effectively delays the attenuation of the flow conductivity of the crack, and improves the final recovery ratio.

Inventors

  • WANG HANYI
  • CHEN YINJIA

Assignees

  • 重庆大学

Dates

Publication Date
20260512
Application Date
20260213

Claims (11)

  1. 1. A fracturing well single well production regulation and control method based on real-time diagnosis is characterized by comprising the following steps: s1, acquiring single well production data of a target production well in real time, wherein the single well production data comprises pressure data and yield data; S2, preprocessing the single well production data; S3, obtaining the effective fracture surface area representing the fracture conductivity through inversion calculation based on the preprocessed single well production data; And S4, generating and executing a regulating instruction for regulating the opening degree of the oil nozzle of the target production well according to the real-time change trend of the effective fracture surface area.
  2. 2. The method according to claim 1, wherein step S1 comprises: s101, acquiring wellhead pressure data of a target production well in real time; S102, acquiring total equivalent yield which is one of yield data and can be acquired based on real-time measurement or based on wellhead pressure data, calculating to obtain continuous estimated yields of oil, gas and water through a virtual flowmeter model, and then calculating to obtain total equivalent yield based on the continuous estimated yields of the three phases; And S103, acquiring bottom hole pressure data which is one of the pressure data, wherein the bottom hole pressure data can be acquired based on real-time monitoring or acquired through back calculation and reconstruction based on wellhead pressure data and total equivalent production.
  3. 3. The method of claim 1, wherein the step of preprocessing the single well production data comprises a data cleaning step based on a dual stage adaptive denoising algorithm, comprising: S201, setting a dynamic threshold based on local variance and statistical distribution characteristics of single well production data, and eliminating coarse errors; S202, performing secondary smoothing on the data with the error removed by adopting a smoothing filter of the self-adaptive window and combining a median filter.
  4. 4. A method according to claim 3, further comprising the step of automatically identifying and segmenting the flow state of the de-noised data after the step of cleaning the data based on the dual stage adaptive de-noising algorithm in the step of pre-processing the single well production data, comprising: s203, calculating a time-varying derivative and a normalized change rate of single well production data; S204, when the time-varying derivative and the normalized change rate exceed the self-adaptive threshold, determining a change point of the production flow state; s205, automatically dividing the continuous time sequence into a plurality of independent flow analysis segments according to the change points, and eliminating invalid data segments with the time length smaller than a preset value.
  5. 5. The method of claim 2, wherein in step S3, the effective fracture surface area characterizing the fracture conductivity is calculated by a fracture diagnosis model inversion, wherein the fracture diagnosis model is configured as a global transient analysis model; The step S3 comprises the following steps: S301, setting a superposition time variable, and constructing a diagnosis chart taking the superposition time variable as a horizontal axis and the corresponding bottom hole flow pressure or bottom hole pseudo pressure as a vertical axis; S302, carrying out linear regression analysis on the data in the diagnostic chart so as to identify linear flow characteristic sections in the data, and acquiring the absolute value of the slope of a regression line of the linear flow characteristic sections; s303, carrying out inversion calculation to obtain the effective fracture surface area based on the absolute value of the slope, wherein the effective fracture surface area is constructed to be inversely proportional to the absolute value of the slope of the regression line.
  6. 6. The method of claim 5, wherein when the target production well is an oil well, the longitudinal axis of the diagnostic map is a bottom hole pressure, and the calculation of the effective fracture surface area is based on the following linear relationship: ; When the target production well is a gas well, the vertical axis of the diagnostic map is the bottom hole pseudo pressure based on real gas, and the calculation of the effective fracture surface area is performed based on the following linear relation: ; In the formula, Is the absolute value of the slope of the regression line, Is the volume coefficient of the crude oil, In terms of the viscosity of the fluid, In order for the reservoir to have a permeability, In order to achieve a degree of porosity, the porous material, In order to integrate the compression coefficient(s), T is the formation temperature for effective fracture surface area.
  7. 7. The method according to claim 1, wherein step S4 comprises: monitoring the change trend of the effective crack surface area; when the attenuation amplitude of the effective crack surface area is monitored to exceed a preset dynamic safety threshold, judging that the crack flow conductivity is damaged, and generating an instruction for reducing the opening of the oil nozzle; When the fact that the effective crack surface area is not attenuated or the attenuation amplitude does not exceed a preset dynamic safety threshold is monitored, judging that the crack flow conductivity is stable, and generating an instruction for maintaining the current opening of the oil nozzle; When the fact that the effective crack surface area is in the ascending trend is monitored, the fact that the crack flow conductivity is healthy is judged, and an instruction for increasing the current opening of the oil nozzle is generated.
  8. 8. The method of claim 7, wherein the dynamic safety threshold is set to a magnitude of effective fracture surface area obtained by inversion prior to a last choke change.
  9. 9. A frac well single well production control system based on real time diagnostics for implementing the method of any one of claims 1-8, comprising: a data acquisition module configured to acquire, in real time, single well production data for a target production well, the single well production data including pressure data and production data; a data preprocessing module configured to preprocess the single well production data; A diagnostic inversion module configured to obtain an effective fracture surface area characterizing fracture conductivity through inversion calculations based on the preprocessed single well production data; And the intelligent decision module is configured to generate and execute a regulating instruction for regulating the opening degree of the oil nozzle of the target production well according to the real-time change trend of the effective fracture surface area.
  10. 10. The system of claim 9, wherein the data acquisition module comprises: The on-site data acquisition device acquires wellhead pressure data and temperature data of the target production well in real time; And the virtual flowmeter module is configured to calculate and output the total equivalent yield of the oil, gas and water phases through a built-in wellbore multiphase flow physical model and a data driving model based on wellhead pressure data and temperature data of the field data acquisition device, and calculate and acquire bottom hole flow pressure data based on the wellhead pressure data and the total equivalent yield.
  11. 11. The system of claim 10, wherein the diagnostic inversion module has a global transient analysis model built into it for performing the following calculations: calculating a superposition time variable based on the production data, and constructing a diagnosis chart taking the superposition time variable as a horizontal axis and the corresponding bottom hole flow pressure or bottom hole pseudo pressure as a vertical axis; Performing linear regression analysis on the data in the diagnostic template to identify linear flow characteristic sections therein and obtain absolute values of slopes of regression lines of the linear flow characteristic sections; And based on the absolute value of the slope, carrying out inversion calculation to obtain the effective fracture surface area.

Description

Fracturing well single well production regulation and control method and system based on real-time diagnosis Technical Field The invention belongs to the technical field of unconventional oil and gas field development and intelligent control intersection, and particularly relates to a single well production regulation and control method and system for shale oil and gas and other fracturing wells. Background Unconventional oil and gas resources such as shale oil and gas have become an important component of global energy supply. Such reservoirs typically have very low matrix permeability and therefore their development is highly dependent on horizontal well drilling techniques and large scale hydraulic fracturing techniques. The construction of a complex artificial fracture network in a tight reservoir through hydraulic fracturing is a precondition for realizing commercial exploitation of shale oil and gas. Shale reservoirs, however, typically have extremely strong stress sensitivity. During production, as formation fluids are produced, pore pressure decreases, resulting in a significant increase in the effective stresses acting on the rock matrix and fracture faces. This increase in effective stress can cause proppant embedment, fracture, and closure of unsupported fractures, which in turn can lead to irreversible damage to fracture conductivity (or effective fracture surface area). Therefore, the establishment of a scientific and reasonable production system (namely, the accurate control of the opening degree of the oil nozzle) is very important for delaying the attenuation of the diversion capacity of cracks and improving the final recovery ratio (EUR) of a single well. The existing shale oil gas well production regulation technology mainly has the following limitations: First, the regulation strategy is static and lacks single well pertinence. Existing "pressure control production" regimes typically set a uniform production pressure differential window (e.g., providing that the daily wellhead pressure drop does not exceed a particular value) based on static geological parameters of the block or limited numerical simulation results. This "one-shot" mode of management ignores the strong differences in geologic heterogeneity and single well fracturing effects. For wells with better geological conditions and stable fracture support, excessive pressure control can limit capacity release, while for wells with extremely strong stress sensitivity, uniform pressure drop rates may still result in premature fracture closure. In addition, this model cannot accommodate the dynamic changes in production regime required by a single well at different life cycles (e.g., early linear flow phase and late boundary control flow phase). Second, feedback is delayed, relying on manual analysis. Current evaluation of fracture conductivity or effective fracture area relies primarily on production transient analysis (RTA) or well test analysis (PTA). These conventional methods typically require off-line analysis by a professional engineer after production data accumulated for weeks or months is exported. In the face of complex working conditions such as frequent on-site switching of wells, oil nozzle adjustment and the like, traditional analysis plates (such as logarithmic-logarithmic diagrams or square root time diagrams) often fail due to serious data scattering, and accurate conclusion is difficult to obtain. Although global transient analysis (UTA) theory proposed in recent years shows advantages in terms of processing variable flow data, the current technology still mainly stays in a theoretical model or a post analysis stage, lacks matched automatic denoising, segmentation and feature recognition algorithms, and cannot meet the closed-loop control requirements of real-time diagnosis and real-time feedback of an industrial field. Furthermore, the field multiphase flow data has low quality, and the inversion accuracy is affected. Accurate fracture parameter inversion is highly dependent on high quality bottom hole flow pressure (BHP) and hydrocarbon-water three-phase production data. However, most shale oil and gas wells are not installed with downhole permanent pressure gauges for cost reasons, and the surface lacks expensive multiphase flow meters (MPFM) or test separators. Existing production data typically contains a lot of noise, outliers and data loss due to artificial intermittent metering. The existing regulation and control system generally lacks an effective data complement (such as virtual metering) and a high-fidelity cleaning mechanism, and the analysis is directly performed based on inferior data, so that wrong decisions are often caused. In view of the foregoing, there is a need for an intelligent method and system that can accurately invert the downhole fracture health in real time using low cost conventional surface monitoring data, and automatically adjust the production regime accordingly, to achieve refined