Liu Yinan, Wang Li, Xu Yanyong, Zong Peng, Dong Yu
China United Coalbed Methane Corp., Ltd., Beijing 100011, China.
China National Offshore Oil Corp., Beijing 100010, China.
ACS Omega. 2024 Feb 14;9(8):9577-9584. doi: 10.1021/acsomega.3c09453. eCollection 2024 Feb 27.
The roof aquifer of the Carboniferous Taiyuan Formation coal beds in the Liulin area severely restricts the development and utilization of coalbed methane (CBM). A method for quantitatively predicting high-water-production areas was established by analyzing the relationship between the geophysical logging data and water production. The results showed that the logging profile of the limestone aquifers in high-water-production wells was unique, with high acoustic velocity (AC), high γ-ray values (GR), and low resistivity (Rd). The developed pores and fractures in the roof limestone increase the interval transit time. The formation water in the pores and fractures of the roof limestone decreases the resistivity. The clay filling in the pores and fractures of the roof limestone originated from the dissolution product of limestone and hydrodynamic transportation, which resulted in increased GR values. Furthermore, the representative natural GR log data were used to calculate the clay content in limestone, which indicated that the clay content in limestone had a positive correlation with the water yield of the CBM wells. The water-bearing characteristics of roof limestone showed that the water content was higher in the northern area and decreased gradually toward the south. The method for predicting the high-water-production area was helpful for the CBM exploration and production.
柳林地区石炭系太原组煤层顶板含水层严重制约了煤层气（CBM）的开发利用。通过分析地球物理测井数据与产水量之间的关系，建立了一种定量预测高产区的方法。结果表明，高产水井中石灰岩含水层的测井曲线具有独特性，声速（AC）高、γ射线值（GR）高、电阻率（Rd）低。顶板石灰岩中发育的孔隙和裂缝增加了声波时差。顶板石灰岩孔隙和裂缝中的地层水降低了电阻率。顶板石灰岩孔隙和裂缝中的黏土充填物来源于石灰岩的溶解产物和水动力运移，导致GR值升高。此外，利用具有代表性的自然伽马测井数据计算石灰岩中的黏土含量，结果表明石灰岩中的黏土含量与煤层气井的产水量呈正相关。顶板石灰岩的含水特征表明，北部地区含水量较高，向南逐渐降低。该高产区预测方法有助于煤层气的勘探与开发。
