二氧化碳无水压裂增产机理研究  

Mechanisms of CO_2 Water-free Fracturing Method in Production Increasing

作　　者：段永伟 张劲[2] DUAN Yongwei;ZHAN Jin(Research Institute of Oil and Gas Engineering, PetroChina Jilin Oil and Gas Field Company, Songyuan, Jilin 138001;School of Petroleum Engineering, China University of Petroleum, Beijing 102249)

机构地区：[1]吉林油田公司油气工程研究院,吉林松原138001 [2]中国石油大学(北京)石油工程学院,北京102249

出　　处：《钻井液与完井液》2017年第4期101-105,共5页Drilling Fluid & Completion Fluid

摘　　要：单井控制范围有限和地层能量补充困难一直是困扰致密油储层开发的关键问题。压裂过程井下微地震数据监测表明,二氧化碳无水压裂改造体积是同等液量常规水基压裂的2.5倍,并能显著增加裂缝的复杂程度。室内实验和压后原油取样分析证实,二氧化碳能够有效降低原油黏度,通过无水压裂施工实现了原油混相,提高了驱油效率。压后地层静压测试显示,压后地层压力较压前有显著提高,具有单井超前补充地层能量的效果。二氧化碳无水压裂技术已在吉林油田成功应用5口致密油井进行了应用,这些井压裂后产油量均较压前有显著提高,平均单井日增油量2.31t,且施工后邻井产油、产液量均有不同程度的提高。说明了二氧化碳无水压裂增产效果良好,该技术在致密油藏开发中具有广阔的前景。Limited control range of a single well and insufficient formation energy supplement have long been critical problems affecting the development of tight oil reservoirs.Monitoring of downhole micro seism data during fracturing operation indicates that the volume of formation stimulated with CO2water-free fracturing is2.5times of the volume of formation stimulated with conventional hydraulic fracturing using the same volume of water as that of the CO2used,and the CO2water-free fracturing creates fractures of increased complexity.Laboratory experiment and crude oil sampling after fracturing operation have proved that CO2can effectively reduce the viscosity of crude oil.With the water-free fracturing,miscibility of crude oil is realized and oil displacement efficiency is enhanced.Static pressure test after fracturing shows that oil production after water-free fracturing is remarkably increased compared with the oil production before fracturing,an effect that is similar to advanced formation energy supplement of a well.CO2water-free fracturing technology has been successfully used on5oil wells with tight reservoir,remarkably increasing oil production after fracturing.Average oil production increase of2.31t/d per well has been gained.The CO2water-free fracturing also caused adjacent wells to produce more oil and more liquid,demonstrating that CO2water-free fracturing,a prospective technology in tight oil reservoir development,is effective in well stimulation.

关 键 词：致密油藏 二氧化碳 无水压裂 增产机理 混相驱油 

分 类 号：TE357.12[石油与天然气工程—油气田开发工程]