摘要
水平井体积压裂是实现页岩气经济开发的有效手段。水力压裂能够形成三维立体复杂裂缝网络,改善页岩气藏渗流环境,但由于页岩气藏基础参数的不确定性,尤其是复杂的孔渗条件、地层温压系统及非线性渗流机理给页岩气压裂缝网反演带来了极大的不确定性,导致准确评估页岩气藏压裂效果困难。本文首先构建了联合直线分析法和图版拟合法的缝网参数确定性反演方法,然后讨论了缝网反演所需基础参数的不确定性,以此提出一种基于马尔可夫-蒙特卡洛方法(MCMC)的页岩气藏压裂缝网不确定反演方法,通过随机生成基础参数样本集,利用确定性方法解释不同样本集下的缝网关键参数,给出其多组合性及概率分布。最后,结合我国西南地区某页岩气区块一口体积压裂水平井的生产动态,明确了压裂缝网四个关键参数的不确定性排序,并反演出了关键参数值及P10、P50、P90的概率结果,评价了由于基础参数的不确定性对压裂缝网参数解释结果的影响程度,对页岩气藏压裂效果评价及合理开发对策制定提供了较全面的实际指导。
Horizontal well combined with volume fracturing technics is an effective means to achieve the economic development of shale gas.Hydraulic fracturing can form a three-dimensional complex fracture network and improve the flow environment of shale gas reservoirs.However,due to the complexity of shale gas reservoir’s basic characteristics,especially the porosity-permeability conditions,formation temperature-pressure system and nonlinear flow mechanism in porous media make the inversion of shale gas pressure fracture network more uncertain,which makes it difficult to accurately evaluate the fracturing effect of shale gas reservoirs.Firstly,based on the dimensionless production solution of shale gas under constant-pressure production conditions,this paper obtained the local solutions of linear flow and boundary control flow in shale gas production process,introduces the mass balance pseudo-time and normalized pseudo-pressure to construct a deterministic inversion method of shale gas fracture network parameters combining the linear analysis method and the chart fitting method,and analysed the uncertainty of basic parameters required for fracture network inversion.The quantitative characterization formulas of uncertain parameters,which include reservoir parameters such as shale porosity and shale permeability et al,the characterization param-eters of shale gas nonlinear flow and adsorption-desorption mechanism and the basic parameters required for inversion,were given respectively in this paper.Moreover,a fracture network uncertain inversion method of shale gas reservoir based on Markov Chain Monte Carlo method(MCMC)was proposed.MCMC sampling method was used to obtain the probability distribution of reservoir parameters,adsorption-desorption and flow parameters,and basic parameters of fracture network.By combining linear flow analysis method and chart fitting method,typical flow stages were identified and fitted to obtain the probability distribution of each inversion parameter.By randomly generating the sample set of
作者
贾品
封皓然
王苏冉
王志凯
牛烺昱
程林松
JIA Pin;FENG Haoran;WANG Suran;WANG Zhikai;NIU Langyu;CHENG Linsong(State Key Laboratory of Oil and Gas Resources and Exploration,China University of Petroleum-Beijing,Beijing 102249,China;School of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)
出处
《石油科学通报》
CAS
2023年第5期637-648,共12页
Petroleum Science Bulletin
基金
国家自然科学基金青年基金“致密储层‘压裂成藏’油水赋存状态变化机理及渗流数学模型研究(No.51004307)”资助。
关键词
页岩气藏
直线分析法
图版拟合
马尔可夫-蒙特卡洛方法
不确定性反演
shale gas reservoir
straight line analysis method
type curve method
Markov Chain Monte Carlo method
uncer-tainty inversion
