Evaluation of unconventional hydrocarbon reserves using petrophysical analysis to characterize the Yageliemu Formation in the Yakela gas condensate field, Tarim Basin, China

The current findings emphasize interpreting wireline logs to assess the hydrocarbon prospect of the Lower Cretaceous Yageliemu Formation in the Yakela (YKL) gas condensate field, Tarim Basin, China. The present study consists of wireline logs of four drilled wells (S4, YK13, YK21, and YK32) and numerous reservoir zones have been comprehended. According to the petrophysical evaluation, the gas-bearing zone has high resistivity values, good porosity (Φeff) and permeability (K), low water content (Sw), and less shale content (Vsh) indicating clean sand. The petrophysical parameters of the interest zones were closely studied which are classed as good-quality sand layers with ranging effective porosities from 4.5 to 10%, permeability ranging from 0.5 to 18 mD, water saturation concentrations ranging from 55 to 59%, and the average value gas is 41–50%. The Archie equation was accurately tested to estimate water saturation in the reservoirs, revealing that in each well, Sw is less than 60%; therefore, the efficiency of the gas-bearing sand is of good quality. Lithofacies, horizontal and vertical variations of reservoir parameters, are evaluated through building self-organizing maps, isoparametric maps of the petrophysical parameters, and litho-saturation cross-plots, respectively. Isoparametric maps assist in visualizing the spatial distribution of the reservoir configuration. It is suggested that more wells be drilled in the southwestern and northwestern parts of the current research area. Due to the high water concentration and shale volume, the northeastern and southeastern portions of the understudied area must be overlooked. Graphical abstract