低渗透油藏水力压裂优化设计方法

STUDY ON HYDRAULIC FRACTURING DESIGN OPTIMIZATION FOR LOW-PERMEABILITY RESERVOIR

低渗透油藏是目前乃至未来很长一段时间里勘探开发的重点领域，水力压裂是开发低渗透油藏的有效方法之一，压裂优化设计方法对压后效果有着极其重要的影响。通过分析低渗透油藏特点和开发中存在的特殊性，制定了低渗透油藏水力压裂优化设计应遵循的基本原则，对渗透率等9个影响低渗透油藏水力压裂压后产量的因素进行敏感性分析，得到各因素影响压后产量的敏感性程度。以国内某低渗透油藏C-A井为例，通过油藏特性分析，结合产量影响因素敏感性分析结果，设计诊断注入测试、低排量支撑剂段塞替挤天然裂缝、短的射孔间隔、压裂液和支撑剂优选、井下微地震裂缝监测，研究制定适合该低渗透油藏的水力压裂优化设计。压裂裂缝监测和压后产量对比表明，压裂设计合理且具有针对性，对低渗透油藏水力压裂设计的制定具有一定的借鉴意义。

Low-permeability oil reservoirs turn to be the significant domain for petroleum exploration and development at present and in the future. Hydraulic fracturing is one of the effective ways to develop them. Particularly production after fracturing is closely related to the design optimization methods. By analyzing the characteristics of low permeability reservoirs and the specialty in the development, the basic principles for hydraulic fracturing design optimization for this kind of oil reservoir are presented and then the sensitivity analysis of the nine factors influencing post -frac production such as permeability etc. are carried out. In the end, the above sensitivity degrees for different factors are obtained. Taking Well C-A in a certain domestic low-permeability reservoir for example, by means of the characteristics analysis of the reservoir and integrating the sensitivity analysis results of production influencing factors, the diagnostic injection test, low rate proppant slug, short perforation interval, fluid and proppant optimization and downhole microseismic fracture monitoring are designed, a hydraulic fracturing optimization design for this kind of low-permeability reservoir is studied and established The monitoring result and the comparison of post-frac production show that the fracturing design is rational and practical, and furthermore its optimization method has a certain reference to the fracturing design of similar low-permeability reservoirs.