›› 2019, Vol. 40 ›› Issue (1): 1-1.doi: 10.7657/XJPG20190117

• 论文 •    

库车坳陷深层裂缝性砂岩气藏可压裂性评价

张辉,尹国庆,王志民,王海应   

  1. (中国石油 塔里木油田分公司 勘探开发研究院,新疆 库尔勒 841000)
  • 出版日期:2019-02-01 发布日期:1905-07-15

Fracability Evaluation of Deep-Burial Fractured Sandstone Gas Reservoir in Kuqa Depression

ZHANG Hui, YIN Guoqing, WANG Zhimin, WANG Haiying   

  1. (Research Institute of Exploration and Development, Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China)
  • Online:2019-02-01 Published:1905-07-15

摘要: 库车坳陷深层裂缝性砂岩气藏经历强挤压构造变形,储集层地应力高,且各向异性强,同时天然裂缝广泛发育,作用于天然裂缝面的地应力严重影响了储集层渗透性能和流体的流动。为优化气井压裂工程方案,从储集层地应力场、裂缝剪应力与有效正应力之比、岩石脆性及断裂韧性等4个方面,对库车坳陷深层裂缝性砂岩储集层可压裂性进行了评价。根据岩石力学实验、地应力场建模及天然裂缝剪切变形能力对压后产能的影响分析,建立了一种适用于高应力背景裂缝性砂岩储集层的可压裂性指数评价模型。相对基于岩石脆性和断裂韧性可压裂性评价模型,其更多考虑了现今地应力场和天然裂缝对压裂效果的影响,对高应力背景裂缝性致密储集层井间和层间压裂难易程度反映更敏感,可用于压裂段优选、射孔位置确定、注入压力选择、泵注程序优化等。可压裂性评价技术在库车坳陷气井中成功应用30井次,为需要储集层改造气井的定量化压裂方案优化提供了依据。

Abstract: The deep-burial fractured sandstone reservoir in Kuqa depression has experienced strong compressional structure deformation, which is characterized by high magnitude of in-situ stress, strong anisotropy and widely developed of natural fractures. The in-situ stress on natural fracture surface seriously impacts the permeability and fluid flowing in the reservoir. To optimize fracturing stimulation program for gas wells,a research on fracability evaluation is conducted in terms of four geomechanics parameters including in-situ stress, shear-to-effective normal stress ratio on natural fracture, rock brittleness and fracture toughness for the deep-burial fractured sandstone reservoir in Kuqa depression. Based on rock mechanics testing, stress field modeling and analysis of the influence of shear deformation ability of natural fractures on gas well performance after fracturing, a fracability index evaluation model suitable for the fractured tight sandstone with high stress is established. Compared with other fracability models based on rock brittleness and fracture toughness, the new model considers the influences of present in-situ stress and natural fracture on fracturing effect, which is more sensitive to the well-to-well and layer-to-layer fracabilities in the fractured tight reservoir with strong stress, and can be used to optimize fracturing interval, determine perforation location, select injection pressure and optimize pump injection procedure, etc. The fracability evaluation technology has been successfully applied in 30 gas wells in Kuqa depression, which provides basis for quantitative fracturing program optimization in the gas wells which need to be stimulated

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