川南威远地区页岩气开发工厂化作业模式

A factory-like shale-gas development mode for Weiyuan area, southern Sichuan Basin

中国非常规油气资源丰富,为了在低渗透的页岩气资源开发过程中有效降低施工成本、提高作业效率、缩短开发周期,以四川盆地南部威远地区页岩气工厂化钻完井作业技术为研究对象,开展北美地区页岩气大规模应用作业模式研究,由于国内页岩气开发存在着人口居住密集,山地丘陵环境复杂,作业期间资源共享率低、水资源占用多、施工工序多、效率低等难题,指出不能照搬国外开发模式,需要形成一种适应于国内情况的页岩气区域工厂化作业模式。研究结果表明:(1)井位平台、设备材料等应进行工厂化部署;(2)水/电资源区域应统一调配;(3)同一区块、同一页岩气施工平台多口井人员、设备应实现共享;(4)钻井液、压裂液应进行重复利用;(5)优化钻完井作业配套技术。结论认为:(1)初步建立流水线作业流程,进一步探索区域工厂化作业模式,已实现钻完井作业无缝衔接,设备安装时间缩短70%,设备利用率达到100%,压裂返排液重复利用率在90%以上,钻井液重复利用率在80%以上,作业效率提高1倍以上;(2)页岩气区域工厂化作业模式探索为加快国内页岩气勘探开发提供了技术支撑。

There are abundant unconventional oil and gas resources in China. In order to effectively reduce construction cost, improve operation efficiency, and shorten development cycle in the development process of low-permeability shalegas resources, based on one large-scale shale-gas development mode used in North American, another factory-like mode was established for Weiyuan shale gas in southern Sichuan Basin. However, in China, dense population and complex mountainous environment lead to some difficulties in shale-gas development, such as low sharing rate during resource development, too much occupation on water resources, mulitple construction procedures, and low efficiency. So, this foreign mode shall not be copied, and it is necessary to establish the domestic factory-like shale-gas development mode. Results show that(1) well location, drilling platform, equipment, and materials shall be involved in this factory-like mode;(2) water/power resources shall be unified in one region;(3) not only personnel but also equipment in some drilling at the same block along with platform shall be reused;(4) drilling and fracturing fluid shall be recycled;and(5) some support technologies of drilling and completion shall be optimized. In conclusion, the pipelining operation flow is preliminarily established, the regional factory-like mode is explored further, the seamless connection of drilling and completion is realized, the equipment installation time is shortened by 70%, the equipment utilization rate is up to 100%, the recycling rate of both flowback fracturing and drilling fluid is individually over 90% and 80%, and the operation efficiency is increased by more than 100%. What’s more, this factory-like shale-gas development mode may provide effective technical support for speeding up shale-gas exploration and development in China.