沁水盆地寿阳区块煤层气排采动态成因机理及排采对策

发布时间：2019-01-02 09:16

【摘要】：以寿阳区块的静态地质资料和动态排采资料为基础,分析了寿阳区块的排采动态特征并从系统分析观和地质因素2个方面解释了排采动态的成因机理,提出了寿阳区块的排采对策。研究表明:寿阳区块排采动态呈现出单井产水量高,产气量低或不见气的特点,合层排采井的典型日产水量大于单采井产水量之和,表现出“1+12”的现象;典型日产气量与典型日产水量呈现负向包络关系,高产水对产气有抑制作用;造成寿阳区块煤层气井高产水的原因有2个,一是寿阳井筒—排采煤层系统为开放系统,断裂或压裂缝沟通煤层上下的含水层,造成煤层气井低效降压;二是寿阳区块煤系地层中分支河道砂体发育,且因该区发育的断裂多为高倾角断裂,当多层合层排采时,断裂沟通含水层的概率大大上升。因此,在培育高产气井时,首先要避开断层开放型系统,远离断层,其次是避开垂直压裂缝压穿型系统,因寿阳区块煤层更易压裂,故压裂时要适当降低前期采用的压裂规模,针对具体井层,需根据顶底板隔水层的厚度,保证在不压穿顶底板隔水层的前提下,优化压裂规模,以实现在规避围岩含水层不利影响的条件下最大程度地改善煤储层的渗透率。
[Abstract]:Based on the static geological data and dynamic discharge data of Shouyang block, the dynamic characteristics of drainage in Shouyang block are analyzed, and the formation mechanism of drainage is explained from two aspects of system analysis and geological factors. The countermeasures of discharging production in Shouyang block are put forward. The study shows that the drainage performance of Shouyang block is characterized by high water production and low or no gas production in single well. The typical daily water production of combined production wells is larger than the sum of water production in single production wells, showing the phenomenon of "112". There was a negative envelope relationship between typical daily gas production and typical daily water production, and high yield water could inhibit gas production. There are two reasons for the high water production of coalbed methane wells in Shouyang block. One is that Shouyang wellbore-drainage coal seam system is an open system, fracture or pressure fracture connects the aquifer up and down the coal seam, resulting in low effective pressure reduction of coalbed methane wells; The second is the development of branch channel sand body in the coal measure strata of Shouyang block. Because the faults developed in this area are mostly high-dip faults, the probability of the fault communicating aquifer increases greatly when the multi-layered strata are discharged. Therefore, in cultivating high production gas wells, first of all, we should avoid the open fault system, away from the fault, and secondly avoid the vertical pressure fracture pressure system. Because the coal seam in Shouyang block is easier to fracturing, the scale of fracturing used in the early stage should be reduced appropriately when fracturing. According to the thickness of the top and bottom water barrier layer, the fracturing scale should be optimized under the premise of not pressing through the roof and bottom plate water barrier layer. In order to improve the permeability of coal reservoir to the maximum extent under the condition of avoiding the unfavorable influence of surrounding rock aquifer.
【作者单位】：中国石油大学(北京)地球科学学院;油气资源与探测国家重点实验室;中海石油(中国)有限公司非常规油气分公司;中联煤层气有限责任公司;中海石油(中国)有限公司非常规油气管理处;
【分类号】：TE33+2

【相似文献】