一种煤岩储层保护装置的研制与应用

Development and application of a coal reservoir protection device

王凤清 韩军 王辰龙 张康 徐贵东 刘国强

WANG Fengqing HAN Jun WANG Chenlong ZHANG Kang XU Guidong LIU Guoqiang

中石油煤层气有限责任公司临汾分公司 中国石油冀东油田公司南堡作业区 陕西鼎和源瑞环境工程有限公司

Linfen Branch of PetroChina Coalbed Methane Company Limited, Taiyuan, Shanxi 030000, China Nanpu Operation Area of PetroChina Jidong Oilfield Company, Tangshan, Hebei 063200, China Shaanxi Dinghe Yuanrui Environmental Engineering Co. Ltd., Xi’an, Shaanxi 710068, China

煤岩储层大的比表面积、较强的应力敏感和吸附能力导致其更易受到伤害，进而影响煤层气采收率。为减少修井过程对煤岩储层造成的伤害，设计了煤层气井用煤岩储层保护装置。该装置主要由单流阀、中心管、弹簧和弹簧外管组成，单流阀控制地层液向井筒单向流动，中心管、弹簧和弹簧外管相互配合，修井时可以利用压差的增大关闭井筒内井液流道，实现隔绝储层的目的。前期在3 口井进行了试用，作业后产气均恢复至原有水平，产气恢复时间缩短为原来的15%，说明该装置能有效隔绝储层，实现保护储层的目的，为煤层气井修井过程中的煤岩储层保护提供了新的方法和思路。

Coal reservoirs can be damaged easily due to the large specific surface area, high stress sensitivity and strong absorbability.Eventually, the coalbed methane (CBM) recovery factor is adversely affected. A coal reservoir protection device for CBM wells was developed to reduce the damage on coal reservoirs during the workover. According to its design, the valve assembly which is used to control the unidirectional flow of fluids in well, works together with the springs in central tube to shut in the flow path in hole with the increasing of pressure difference. In this way, the reservoir is isolated, while the CBM well can perform continuous stable production.The device was tested in 3 wells. As a result, it only took 15% of the original time for the gas production to recover to the previous level.This indicates that the device can isolate and protect the reservoir effectively. Furthermore, it provides a new method and idea for coal reservoir protection during the workover of CBM wells.

10.13639/j.odpt.2016.03.025