蒙古国勘探区块的凹陷、区带、圈闭定量评价方法

Quantitative evaluation method of the sag,play and trap in Mongolia exploration blocks

海外油气勘探往往需要快速评价、快速上钻、快速上产,开展地质风险评价有利于勘探决策、规避风险。基于蒙古国境内50个凹陷、35个区带和301个圈闭资料,借鉴海拉尔盆地、塔木察格盆地的勘探经验,建立了蒙古国勘探区块“凹陷、区带、圈闭”定量评价方法。研究认为:蒙古国对外放权的勘探区块勘探程度低、地质条件复杂、勘探目标隐蔽性强、勘探难度大、勘探风险高,应用“凹陷、区带、圈闭”定量评价方法统一地质评价标准,有利于实现蒙古国全境尺度上的地质目标优选;经定量评价,从全境50个凹陷中优选Ⅰ类Ⅱ类凹陷共37个、Ⅲ类凹陷13个;Ⅰ类Ⅱ类凹陷中的35个有利区带中进一步优选Ⅰ类区带12个;从301个层圈闭中优选Ⅰ类圈闭135个、Ⅱ类圈闭140个。研究成果对各大石油公司快速评价海外油气勘探区块具有重要指导与借鉴意义。

Overseas oil and gas exploration often needs fast assessment,fast drilling and fast production.The geological risk assessment is beneficial to make the exploration decisions and avoid the risks.Based on the data of 50 sags,35 plays and 301 structural traps in Mongolia and the exploration experiences of Hailer Basin and Tamtsag Basin,a sag-play-trap quantitative evaluation method for Mongolian exploration blocks was established.The researches show that the exploration blocks decentralized by Mongolia are of low degree of exploration,complex geological conditions,high concealed exploration targets with high exploration difficulty and risk.The application of quantitative evaluation method of“sag,play and trap”to unify the geological assessment standards will promote the geological target optimization on the whole Mongolian territory scale.By the quantitative assessments,37 ClassⅠ&Ⅱsags and 13 ClassⅢsags are selected from total 50 sags,12 ClassⅠplays are selected from total 35 favorable plays in ClassⅠ&Ⅱsags,while 135 ClassⅠtraps and 140 ClassⅡtraps are selected from total 301 traps.The research results can provide great guidelines and valuable references for major oil companies to rapidly evaluate overseas oil and gas exploration blocks.