沁水盆地柿庄北区块深部煤储层特征测井评价研究

Study on features and logging evaluation of deep coal reservoir in North Shizhuang Block of Qinshui Basin

基于测井方法解释评价了深部煤储层的顶底板物性、煤体结构、孔隙度和渗透性,研究了沁水盆地杮庄北区块煤储层岩石力学特性、含气性特征和地应力的展布规律。研究结果表明:该区块3煤的顶板物性和封盖性要比15煤的好;3煤的渗透性比太原组15煤的渗透性要好;3煤在研究区西部埋藏深、厚度小,而15煤埋藏相对较深、厚度较大。就地应力而言,3煤在柿庄北区块西南部地应力数值最高,各向异性强,最大、最小地应力差别大;15煤在柿庄北区块西南部地应力数值最高,在北西方向各向异性强,地应力差别大,裂隙发育。最后,对深部煤层气储层特征和深部地应力的变化规律进行了分析,并对测井解释的发展和完善提出了建议。

Based on the logging method,an explanation and evaluation were conducted on the roof and floor physical properties,coal structure;porosity and permeability of the deep coal reservoir.A study was conducted on the rock mechanics features,gas content features and geostress distribution law of the deep coal reservoir.The evaluation results showed that in North Shizhuang of Qinshui Basin,the roof physical properties and sealing of No.3 seam were better than No.15 seam.The permeability of No.3 seam was better than the permeability of No.15 seam in Taiyuan Formation.In the west part of the study area,the depth of No.3 seam was deep and the thickness of No.3 seam was thin.In west part of the study area,the depth of No.15 seam was deep and the thickness of No.15 seam was high.The geostress logging explanation showed that in the south-west part of the study area,the geostress value of No.3 seam was max,the anisotropy of No.3 seam was strong and there was a big difference between the max geostress and the min geostress.In the south-west part of the study area,the geostress value of No.15 seam was max,the anisotropy in the north-west part of the study area was strong,the difference of the geostresses was high and the cracks were developed.Finally,an analysis was conducted on the reservoir features of the deep coalbed methane and the variation law of the deep geostress and the proposals were provided on the development and improvement of the logging explanation.