松辽盆地南部致密气刻度区地质解剖与资源评价关键参数研究——以长岭断陷层龙凤山次凹为例OA

Addressing the key challenge of lacking high-confidence geological calibration zones in resource assessment of tight gas in the southern Songliao Basin,this study focuses on the Longfengshan sub-depression within the Changling fault depression:a region with relatively high exploration maturity.A systematic methodology integrating"geological dissection,parameter quantification,and model validation"was established.Key petroleum system elements including source rock characteristics,reservoir conditions,caprock seal capacity,trap types,and hydrocarbon accumulation conditions were meticulously analyzed.Using a small-grid volumetric method combined with an integrated conventional-unconventional hydrocarbon resource evaluation approach,the resource volumes of the clastic reservoirs in the Yingcheng Formation-Shahezi Formation and the volcanic reservoirs in the Huoshi Formation were quantitatively assessed.Results indicate that the in-place resource volume of the Yingcheng-Shahezi clastic tight gas system is 768.2×108 m3,with a recoverable resource volume of 314.2×108 m3,resulting in a hydrocarbon charge efficiency of 3.7％and a recovery factor of 40.9％.For the Huoshi Formation volcanic tight gas system,the in-place resource volume is 315×108 m3;however,due to rapid lateral facies variations,the recovery factor decreases to 34.4％.This study establishes,for the first time,a methodological framework for calibration zone analysis tailored to the geological prototype of faulted depressions in southern Songliao Basin.The key parameters derived provide a scientific basis for tiered resource potential evaluation of tight gas in the Songliao Basin and analogous complex faulted basins.