There remains a good level of uncertainty in peak gas rate and the time to reach the peak for coalbed methane (CBM) wells owing to reservoir heterogeneity. The novelty of the present study lies in predicting the production behavior of wells in the emerging CBM block of Raniganj through extensive reservoir characterization coupled with reservoir simulation and validation. Ten regional (R–I to R-X) and two local seams intercepted in the six exploratory boreholes drilled in Raniganj Coalfield were investigated. The reservoir characterization approach was used for uncertainty analysis of the key parameters viz. isotherms, gas content, permeability and porosity, and their impact on the production behavior of the CBM wells. Low, mid and high cases of the parameters were determined through regression analysis.

Isotherm and gas content data were experimentally determined while in situ permeability data were obtained from the pressure transient analysis of injection/fall-off test. Reiss model was used for porosity-permeability transformation and Corey's model was used to define the range of relative permeability. The experimental values of Langmuir volume varies between 17.4 and 29.8 cc/gm (daf); Langmuir pressure 2451–7827 kPa; gas content 2.07–13.03 cc/gm (daf); and fracture permeability 0.79–7.12 mD. The model was set up in CMG-GEM simulator to represent a single well producing under commingled completion strategy for all the 12 seams being perforated. Production profiles of both gas and water show a wide range of variation up to 56,201 m³/day and up to 129.84 m³/day, respectively. Data analysis reveals that Raniganj coals are having a wide range of saturation distribution (between 27% and 100%) with a huge upside potential going towards 100% saturation case. Gas content and permeability are found to be the two key factors controlling the CBM production in Raniganj Coalfield. The model results were validated with actual well performance.

由于储层非均质性，煤层气（CBM）井的峰值气速和达到峰值的时间仍然存在很大的不确定性。本研究的新颖之处在于通过广泛的储层表征以及储层模拟和验证来预测Raniganj新兴CBM区块的井的生产行为。研究了在拉尼甘杰煤田钻探的六个勘探井眼中截获的十个区域（RI至RX）和两个局部煤层。储层表征方法用于关键参数viz的不确定性分析。等温线，气体含量，渗透率和孔隙度及其对煤层气井生产行为的影响。通过回归分析确定参数的低，中和高情况。

实验确定了等温线和气体含量数据，而从注入/降落测试的压力瞬态分析获得了原位渗透率数据。Reiss模型用于孔隙度-渗透率转换，Corey模型用于定义相对渗透率范围。Langmuir体积的实验值在17.4和29.8 cc / gm（daf）之间变化；朗缪尔压力2451–7827 kPa；气体含量2.07-13.03 cc / gm（daf）; 和裂缝渗透率0.79-7.12 mD。该模型是在CMG-GEM仿真器中建立的，代表了针对所有12个射孔的混合完井策略的单口井产量。天然气和水的生产曲线显示出很大的变化范围，最高可达56,201 m ³ /天，最高可达129.84 m ³/天。数据分析显示，Raniganj煤的饱和度分布范围广（在27％至100％之间），且朝着100％饱和度的情况具有巨大的上升潜力。瓦斯含量和渗透率是控制Raniganj煤田煤层气产量的两个关键因素。模型结果已通过实际的油井表现进行了验证。