煤系地层陷落柱成因机理与分布规律研究

The Origin Mechanism and Distribution Regularity of Karst Collapse in Coal Measure Strata

司淑平,马建民,胡德西

Si Shuping , Ma Jianmin, Hu Dexi

中原油田分公司煤层气事业部

Coalbed Gas Operating Division, Zhongyuan Oilfield Company, SINOPEC, Henan 457001, P. R. China

煤层气勘探的效益问题, 是近期国内外各界共同关心的热点, 沁水盆地的陷落柱已成为影响该盆地煤层气勘探成效的重要因素之一。为了提高勘探成效, 本文对煤系地层陷落柱的分布规律、成因机理以及陷落柱对煤层含气性影响程度等方面进行了分析与研究, 认为陷落柱一般呈成群集中、定向带状分布, 一般是在具有活跃水动力条件的可溶性岩层地区, 并伴有膏溶、重力与溶洞扩溶等作用的条件下形成的。在认识这些规律的基础上, 提出了避开陷落柱、提高勘探效益的建议。

Benefit of coalbed methane exploration is the commonly concerned focus of personalities of various circles domestic and abroad. Karst collapse is one of the important factors which affect coalbed methane exploration in Qin shui basin. To promoted exploration results of coalbed methane in the basin, in this paper, author analyzes and studies karst collapse’s origin mechanism , distribution mechanism , and karst collapse’s influence on gas content of coalbed in coalbed gas strata. Karst collap se exists commonly in dissolved rock area with active hydrodynamics condition, and formed under the condition of gypsum karst, gravity and karst cave dissolution, and is in concent rated, directional and banded distribut ion. On the basis of these regularities, we put forward to the proposals how to avoid karst collapse and improve exploration benefit.