吐哈盆地中低阶深部煤储层地质特征及有利层段优选——以柯新1H井为例OA

The optimal selection of favorable reservoir is a fundamental and necessary task after logging and before fracturing operations,which can help improve the success rate of coalbed methane explora-tion.The target coalbed reservoir of the first coalbed methane exploration well,Kexin1H,in the Tur-pan-Hami Basin is located at a depth of 3 163～3 350 meters.The geological characteristics analysis and optimal selection of a favorable reservoir of coalbed methane are of great significance for subsequent exploration and development.This study conducted more than 270 tests on coal quality,coal structure,in-suit gas content,as well as isothermal adsorption,porosity,permeability,stress sensitivity,rock mechanics,and other parameters,providing a comprehensive understanding on the deep coalbed meth-ane reservoir in the Turpan-Hami Basin and a deep analysis on optimal selection of favorable reservoir.The results show that:① coals in the Xishanyao Formation drilled by Kexin1H well have a vitrinite re-flectance ranging from 0.64%to 1.02%,with vitrinite content ranging from 63.40%to 89.57%.Based on the industrial analysis results of coal-rock,it is believed that the main coal seam is a long-flame coal or non-caking coal reservoir;② based on the measurements of closed-core and isothermal adsorption,the gas saturation of coal rock reservoir ranges from 1.47 to 1.98.The three-axis elastic modulus and Poisson's ratio of coal rock are between 3.594 GPa to 7.795 GPa and 0.17 to 0.27,re-spectively.The coal structure is mainly fractured coal and granular coal.The coal rock reservoir be-longs to the over-saturated,medium-low rank,fractured-soft,low-permeability,and strong stress-sen-sitive reservoir;③ an evaluation index system for the optimal selection of a favorable reservoir in a sin-gle well based on fuzzy analytic hierarchy process was developed,which includes three main categories of primary indicators and twelve secondary indicators.It is believed that the producibility of the coalbed reservoir in the third section of Well Kexin 1H is high in production potential.However,attention should be paid to the impact of coal fines during engineering operations.