摘要
我国煤储层与美国煤储层特性不同,与常规油气储层特性及产出特点也有较大的差异,由于在制定适合我国煤层气储层特性及开采特点的固井技术上缺乏针对性,导致后期开采存在诸多难题。从煤层地质及工程因素的角度出发,对国内固井技术及存在的问题进行深入调研分析,指出了我国煤层气固井的难点、固井工艺及水泥浆体系应具备的特性,并提出了从煤层特性及开采角度出发,研究满足后期压裂以及储层改造的固井工艺及水泥浆体系,优选出煤岩吸附量少、早期强度高、保护储层,对渗透率影响小且外加剂在低温下配伍性好的水泥浆体系;建立固井工艺及水泥浆对煤层压裂裂缝影响的诊断与评估技术体系,合理设计水泥浆密度,实现近平衡压力固井,保护煤层等建议。
For coal reservoirs in China, their characteristics are very different from not only those in USA but also those of conventional reservoirs. Especially in China, some existing cementing technologies are not well suitable for coal reservoirs and their exploitation, resulting in a lot of difficulties occurring during later exploitation. In this paper, some cementing technologies are further studied based on reservoir geology and engineering. The cementing difficulties and technologies, and cement-slurry system are pointed out. Meanwhile, some suggestions are made: (1) the cementing technology and cement-slurry system should be developed to meet with both later fracturing and reservoir reconstruction; (2) with an ability of reservoir protection, the system should be optimized and is characterized by a little adsorption to coal rock, high intensity in early stage, very little impact on permeability and better compatibility under low temperature for its additive; (3) another system to diagnose and evaluate the effect of cementing technology and cement-slurry system on fracturing fracture should be established, and the slurry density should also be designed torealize near-balanced pressure cementing and protect coal reservoirs.
出处
《天然气技术与经济》
2011年第6期26-28,78,共3页
Natural Gas Technology and Economy
关键词
煤层气
固井
水泥浆
固井工艺
CBM, cementing, cement slurry, cementing technology
