Play Assessment And Prediction Of Oil And Gas Resources In Liaodong Bay Area

After several decades of oil and gas exploration,the assessment of oil and gas resource and prediction of favorable zone have been carried out for several times in Liaodong Bay area,but the following problems still exist:data of the latest drilling and exploration have not been supplemented and applied;In this project,the application of the seismic data has brought new understanding of the deep source rocks and the potential of oil and gas resources in the area.The predecessors'studies have not deeply studied the conditions of hydrocarbon accumulation in the oil and gas zones,and the division of zones is not clear,so the accuracy of prediction of favorable zone is generally low;The allocation of remaining oil and gas resources has not been well resolved.In view of the above problems,based on the latest understanding of the boundary conditions and hydrocarbon generation parameters of deep source rocks in the project,we estimated that the amount of oil and gas resource in Liaodong Bay area is 3.512 billion tons by the basin simulation,and use the exploration benefit method to constraint the prediction of oil and gas resources.Based on the discussion and analysis of parameters of controlling oil and gas accumulation,we established parameter system of play assessment suitable for Liaodong Bay area including 18 parameters,then we re-divided Liaodong Bay area into 8hydrocarbon accumulation zones and made a comprehensive and quantitative evaluation.Based on the play evaluation,taking trap group as a basic unit,the five major favorable strata of N₁g,E₃d₂,E₃d₃,E₃s₂ and E₂s₃ are divided into 137 trap groups,and we evaluated quantificationally the geological conditions of each trap group and allocated remaining amount of oil and gas resource.Finally,based on the value of comprehensive evaluation,results of the evaluation can be divided into three levels.The evaluation results show that:Class I?The comprehensive evaluation value is greater than 0.4?,there are 15 trap groups,which are mainly distributed in the north of Liaoxi uplift and the north of Liaodong uplift.This type of trap group is the key target for exploration of the next step in the region;Class II?comprehensive evaluation value 0.2-0.4?,There are 26 trap groups in class,which are mainly distributed in the Liaozhong strike-slip zone,Liaodong uplift and Liaoxi slopes.The group is the target of medium and long term exploration.Class III?the comprehensive evaluation value is less than 0.2?,There are 77 trap groups,which have relatively poor condition of accumulation of oil and gas.The result of the evaluation provides more accurate and favorable target prediction for the Liaodong Bay area and can provide valuable reference for the recent exploration direction.