111 / 2023-12-30 23:01:38

Three-Dimensional Petrophysical Properties Modeling and Prospective Area Evaluation of Kailashtila Gasfield in Surma Basin, Bangladesh

Petrophysical properties; 3D modeling; Kailashtila; Surma Basin

Kailshtila, situated in the Surma Basin, is among the largest gas fields that experienced high initial production, having been actively extracting gas since 1983. However, recent observations indicate a decline in gas production, with only 3 out of 7 wells currently active due to issues like diminished wellhead pressure and excessive sand and water influx during extraction. In the present study, the petrophysical modelings of the Kailashtila gasfield were done to interpret vertical and spatial propagation of petrophysical properties to characterize the reservoirs for future development of enhanced gas production using 24 seismic sections and well-log data from 4 wells. Three primary gas-bearing reservoirs, upper gas sand (UGS), middle gas sand (MGS), and lower gas sand (LGS), exist in the field. Key petrophysical properties, including shale volume, porosity, permeability, and saturation, have been assessed, leading to constructing a 3D petrophysical properties model using Petrel software. The UGS, dominated by sand with a lower part more shaley, exhibits good effective porosity, permeability, and sufficient gas saturation. The MGS and LGS are characterized by clean sandstone, low shale content, favorable porosity and permeability, and considerable gas saturation. With the production from these reservoirs, the gas water contact (GWC) moves up, leaving a very limited gas-saturated area. The qualitative and quantitative data and structural and petrophysical models show that the UGS and MGS reservoirs are more promising than LGS reservoirs for further development of enhanced production. Based on the petrophysical and GWC models, four prospective zones were identified to further develop the UGS and MGS reservoirs. This study aims to provide significant information for future field development in the Kailashtila gas field and the gas fields in the Surma Basin.