构造煤U型对接井水平段钻井技术

Drilling technology for the horizontal section of the intercept well in structural coal

摘要:

煤层气是一种非常规天然气资源，传统的煤层气开采方式为地面直井排水降压开采，但这种方式开采煤层气单井产量低、经济效益比较差。U型对接井是一种煤层气开采钻井技术，是由一口直井和一口水平井对接组成，水平井可以在煤层或煤层顶底板与直井连通，目前大多数水平井沿着煤层钻进。煤层气水平井是一种成本不是很高但增产效果非常好的技术，已经越来越多地应用于煤层气的开采。文中主要介绍U型对接井构造煤水平段钻井技术，此地煤层结构形成了局部的碎裂煤、碎粒煤和糜棱煤等构造分层，煤层稳定性较差。在该地质条件下U型对接井钻完井取得成功，对进一步丰富煤层气开发技术和推动高、中、低煤阶煤层气的全面开发，具有非常重要的意义。

Abstract:

Coalbed methane is an unconventional natural gas resource. Traditionally it is extracted by surface drilled vertical wells through water drainage and depressurizing， but this method has low output and poor economic benefit. The intersected well set is a kind drilling technology for coalbed methane mining， which is composed of a vertical target well and an intercept horizontal well. The horizontal well can be connected with the vertical well inside the coal seam ，or in the roof or bottom of the coal seam； while at present， most horizontal wells are drilled inside the coal seam. Coalbed methane horizontal wells are a kind of technology which is not very expensive but can increase production effectively. It has been used more and more in coalbed methane mining. This paper introduces drilling technology for the horizontal section of the intercept well in structural coal where the coal seam structure has formed local structural stratification， such as broken coal， broken coal， chlamy coal， and the stability of the coal seam is poor. The successful completion of the intersected well set under this geological condition is of great significance to further enrich the development technology for coalbed methane and to promote the overall development of high-，medium- and low-rank coalbed methane.