Shale oil and gas integration output analysis method based on dynamic leakage flow volume

Abstract

The present invention discloses a shale oil and gas integration output analysis method based on a dynamic leakage flow volume. The method comprises: arranging and preparing data; preliminarily estimating a limit leakage flow volume and effective fracture half-length, and calculating a dynamic leakage flow volume, a reservoir average pressure change and pressure correction factors; drawing an output normalization pseudopressure curve, calculating a fluid diffusion coefficient in a fracture reconstruction area, drawing a square root time characteristic curve, calculating the effective fracture half-length, and determining the limit leakage flow volume and the final output degree according to the correction Duong method; if the effective fracture half-length and the limit leakage flow volume calculation value are very different from an input value, substituting the calculation value into the step 2 again to perform circulation until the convergence is consistent so as to obtain the accurate effective fracture half-length and the limit leakage flow volume; substituting a dynamic leakage flow volume formula into a macroscopic material balance model, and performing comparison to obtain the accumulation contribution of the size of the fracture reconstruction area to the shale oil and gas production; and determining an optimal fracture horizontal well fracture interval and an optimal well spacing. The shale oil and gas output dynamic analysis and evaluation accuracy is improved.

Description

technical field [0001] The invention relates to the technical field of oilfield development and optimization, in particular to a method for analyzing comprehensive production of shale oil and gas based on dynamic drainage volume. Background technique [0002] In the process of shale oil and gas development, historical production analysis of production wells is an important means to obtain formation information, evaluate production quality and optimize oil and gas production. However, complicated factors such as complex reservoir characteristics of shale oil and gas, dynamic desorption of oil and gas, non-Darcy flow at micro-nano scales, and fracture closure and shale shrinkage during production all make the existing traditional oil and gas dynamic analysis methods ineffective. Then it is applied accurately, which brings difficult challenges to the evaluation and optimization of shale oil and gas development by using production data. [0003] The main reasons are: (1) The ex...

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Problems solved by technology

However, complicated factors such as complex reservoir characteristics of shale oil and gas, dynamic desorption of oil and gas, non-Darcy flow at micro-nano scales, and fracture closure and shale shrinkage during production all make the existing traditional oil and gas dynamic analysis methods ineffective. Then apply it accurately, which brings difficult challenges to the evaluation and optimization of shale oil and gas development by using production data

[0003] The main reasons are: (1) The existing methods are suitable for simple well types and conventional fractured wells, and it is difficult to accurately characterize the production performance of volumetric fractured horizontal wells used in shale oil and gas development

(2) Existing methods do not couple complex distribution attributes of nanoscale matrix pores and multi-scale fracture networks in shale oil and gas

(3) The existing method does not couple the effects of shale oil and gas decomposition, adsorption and non-Darcy seepage characteristics on the production of production wells

(4) The existing method is based on the assumption of steady-state flow of reservoir fluid; however, the shale permeability is extremely low, it is difficult to reach the steady-state flow stage in a short period of time, and it is in the transient flow stage throughout the production life, which makes the existing method no longer applicable

(5) The existing method does not consider the influence of dynamic damage changes of reservoir rocks and fractures on production during the development process; while shale oil and gas wells have rapid production decline and rapid pressure depletion, resulting in large rock shrinkage and rapid pressure failure in shale oil and gas reservoirs Crack closure damage, not negligible

(6) Existing methods are difficult to simultaneously optimize predictions based on historical data and achieve coupling analysis of real-time evaluation and predictions

Therefore, conventional oil and gas dynamic analysis methods are not suitable for shale oil and gas, and may even bring large errors, which pose a difficult challenge for the effective and optimal development of shale oil and gas

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