Offshore fractured horizontal well post-fracture effectiveness evaluation method

Abstract

The present invention discloses an offshore fractured horizontal well post-fracture effectiveness evaluation method. The method comprises establishing a matrix linear flow equation; calculating an initial fracture half-fracture length and an initial fracture gap according to the established matrix linear flow equation; establishing a numerical model based on the calculated initial fracture half-fracture length and the initial fracture gap; and fitting a daily gas production and a cumulative gas production through numerical simulation based on the established numerical model, and adjusting the initial fracture half-fracture length and the initial fracture gap according to the fitting result, so as to realize complete fitting. Through the above technical scheme, an evaluation method which combines a horizontal well multiple fracture analytic model and a horizontal well multiple fracture numerical simulation is provided, and multiplicity of the numerical model can be avoided while the accuracy of an analytic solution can be raised.

Description

technical field [0001] The invention relates to the technical field of fluid extraction from wells, in particular to a method for evaluating post-fracture effects of offshore fracturing horizontal wells. Background technique [0002] Offshore fracturing technology is the key to the success of the development of offshore low-permeability gas reservoirs, and whether the fracturing operation meets the design requirements is directly related to the production of fracturing wells. However, in order to accurately evaluate whether the fracturing operation meets the design requirements and provide a basis for later production prediction, it is necessary to provide a complete set of post-fracturing evaluation methods. How to solve these problems is the key to the success of offshore fracturing applications. [0003] In the 1980s, domestic and foreign researchers began to study the fracturing stimulation technology of horizontal wells. The commonly used means to obtain the fracture ...

AI Technical Summary

Problems solved by technology

The commonly used means to obtain the fracture parameters of fracturing horizontal wells are microseismic monitoring and net pressure fitting to calculate formation fracture parameters. Microseismic monitoring technology is a new geophysical technology that has emerged in the past 20 years. Geophones are arranged on the ground to receive the micro-seismic events generated during the initiation process, and parameters such as the location of the micro-seismic source are obtained by inversion of these events. However, geophones cannot be deployed in offshore fracturing horizontal wells, so micro-seismic monitoring technology cannot Offshore implementation; net pressure fitting is mainly to obtain fracture parameters by fitting the net pressure data generated during fracturing construction. The reliability of fracture parameters obtained by this method is poor, and special well test design is required for well testing after fracturing, namely Well shut-in and well start-up operations require special well testing instruments, and production history matching uses numerical simulation technology, so it cannot avoid multiple solutions, so a unique solution cannot be obtained when inverting fracture parameters

[0004] For the above problems, there is no good solution in the prior art

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