基于区带-远景圈闭组合的油气勘探地质风险评价方法

油气勘探的地质风险评价历来就备受油气地质专家和管理层的高度重视，它对降低勘探成本，提高勘探成功率具有重大意义。基于这一出发点，参考国外的经验，依照风险树的分析思想，在充分挖掘了油气勘探地质风险因素的基础上，凝练出了5类23项风险因子，引出了区带-远景圈闭组合风险评价方法。该方法首先确定区带内远景圈闭的平均成功概率，然后赋予单个远景圈闭相对适中的成功概率，计算出整个远景圈闭的平均成功概率大小，最后确定其圈闭的风险大小。这样的研究思路和方法把单个远景圈闭成功概率与区域概率水平有机联系起来，改变了过去一步完成远景圈闭的风险评估的思想，充分考虑了区域评价标准与历史经验，提高了油气勘探地质风险的评价水平和质量，保障了勘探决策的科学性和准确性。通过在济阳坳陷古生界潜山凸起风险评价的应用，得出A带远景圈闭平均成功概率为0.8，这与客观实际吻合良好，说明区带-远景圈闭组合的油气勘探风险评价方法较为客观和科学。

GEOLOGICAL RISK ASSESSMENT METHOD OF OIL AND GAS EXPLORATION ON ZONE AND PROSPECTIVE TRAP COMBINATION

Geological risk assessment, playing an important role reducing the cost and improve the success ratio in oil and gas exploration, has always been thought highly by geologists, experts, and managers. Therefore, taking references from foreign experiences, in light of the analysis way of risk tree, this study took into full consideration all those geological risk factors and classified them into 5 types 23 items in total, and then introduced a geological risk assessment method based on zone and prospective trap combination. This method primarily determined the average success ratio of the prospective traps in a zone, then supposed a certain medium ratio for a single prospective trap, and calculated out the average ratio of the whole prospective traps which could decide on how the risk is for this zone. This method and its idea combined well the success ratio of a single prospective trap with that of the whole zone, having altered the previous idea of one step risk evaluation on the prospective traps. With evaluation standards and historic lessons, this method improved both evaluation level and quality of geological risk assessment ensuring E &; P policy decisions to be made in much more accurate and scientific way. Through its application in Paleozoic buried hill of Jiyang depression, this method calculated the average success ratio was 0.8 for the prospective traps in the zone A, which was in agreement with the practical result.