天然气工业2023，Vol.43Issue(12)：46-54,9.DOI:10.3787/j.issn.1000-0976.2023.12.005
基于微地震约束的多尺度复杂压裂缝网自动反演新方法
An automatic inversion method for parameter determination of multi-scale complex hydraulic fracture network based on microseismic constraint
摘要
Abstract
Multiple-stage horizontal well fracturing is a key technology for the effective exploitation of shale gas reservoirs.However,the fracture network formed by large-scale volumetric fracturing consists of primary and secondary fractures of varying scales,making it extremely challenging to determine the distribution and parameters of these fractures.Therefore,taking microseismic monitoring data as prior constraints,this paper establishes a multi-scale discrete fracture parameter model that takes into account the microseismic event zones and monitoring sensitivity,and constructs a forward model by means of the embedded discrete fracture modeling.In addition,the positions and attribute parameters(e.g.permeability)of multi-scale discrete fractures are automatically inverted and determined using the ensemble Kalman filtering method.And the following research results are obtained.First,the multi-scale discrete fracture parameters of the validation model are inverted and determined to converge near the true values.Compared with the prior statistical moments,the uncertainty of parameters is decreased greatly,leading to the significant improvement of production prediction accuracy.Second,the effective microseismic areas and fracture network parameters in the model of actual fractured horizontal well are inverted and determined by fitting the bottom hole flowing pressure at a constant gas production rate.The coincidence rate of bottom hole flowing pressure rises by 75.7％ during the fitting stage and 82.4％ during the prediction stage.Third,the inverted effective fracture length is half to two thirds of the fracture length shown by the microseismic event point,which indicates a relatively high degree of uncertainty between microseismic data and fracture parameters.Fourth,the posterior value of microseismic monitoring sensitivity is 3.59,suggesting that a significant number of fracturing induced microseismic events may not be reflected in the monitoring data.In conclusion,this method can effectively invert and determine the parameters of multi-scale complex hydraulic fracture networks under the constraint of microseismic data,and is adaptable to microseismic data and fracture network models with high uncertainty.关键词
页岩气藏/压裂水平井/多尺度裂缝/微地震数据/嵌入式离散裂缝模型/集合卡曼滤波/历史拟合/参数反演Key words
Shale gas reservoir/Fractured horizontal well/Multi-scale fracture/Microseismic data/Embedded discrete fracture model/Ensemble Kalman filtering/History matching/Parameter Inversion引用本文复制引用
李俊超,戴城,方思冬..基于微地震约束的多尺度复杂压裂缝网自动反演新方法[J].天然气工业,2023,43(12):46-54,9.基金项目
国家自然科学基金项目"陆相中低熟页岩油原位转化开发裂缝动态演化机理研究"(编号:52204047). （编号:52204047）
