Real-Time Mud Gas Analysis: Optimizing Well Completion, Fluid Composition Predications, and Comparison With PVT Data in Tight Carbonate Reservoir – West Kuwait

The Middle Marrat Formation is a complex tight carbonate reservoir that is known for its heterogeneous composition, varying in rock composition, porosity, and permeability. This variability can have a significant impact on the way fluids move through the formation, making it challenging to achieve consistent measurements of fluid properties using conventional methods across the reservoir. The objective is to overcome the limitations of conventional methods in characterizing fluid properties due to the high-pressure, high-temperature (HP/HT) environment, which complicates well access and data collection. Specifically, the aim is to unlock near real-time indications of reservoir fluid composition, bridging the gap between drilling activity and the arrival of Pressure-Volume- Temperature (PVT) laboratory reports. Mud gas analysis is employed as a valuable tool for predicting fluid properties within the oil and gas industry. This method enables early detection of hydrocarbons during drilling, providing a cost-effective and efficient way to understand the reservoir's characteristics. For the studied wells, due to borehole stability issues, traditional downhole logging was canceled. Consequently, production intervals were determined solely based on mud gas data analysis. The mud gas results were further compared with laboratory results to compare the accuracy of the measurements done at the rig site. The well completion design and subsequent testing confirmed that the most promising production intervals determined by mud gas data had the highest oil production in the field. Moreover, the fluid composition predicted by mud gas analysis matched the composition from the laboratory DST samples. This correspondence highlights the reliability and efficiency of mud gas analysis in providing continuous and accurate fluid composition information, contrasting with the discrete and delayed results of traditional laboratory fluid tests. The findings demonstrate that relying on mud gas analysis for real-time fluid composition inference during drilling led to significant outcomes. The novelty of this study lies in the successful application of mud gas analysis as a primary tool for determining fluid properties and guiding well production strategies in a challenging reservoir environment. By leveraging mud gas data in real-time, the study demonstrates its potential to serve as a crucial source of information for selecting the best completion zones, especially when wireline operations are canceled due to operational complications. This approach offers a practical solution to the limitations posed by HP/HT environments and borehole stability issues, paving the way for more informed and efficient reservoir management practices.