成熟探区主力含油层系储量空白区勘探目标优选方法 ——以渤南洼陷南斜坡沙三段为例

济阳坳陷已进入勘探成熟甚至高成熟阶段,针对成熟探区主力含油层系储量空白区勘探日益增加的难题,以渤南洼陷南斜坡沙三段为例,建立一套适合于成熟探区主力含油层系储量空白区勘探目标优选方法,并将其定义为"七步走"评价方法。该方法在运用地质帕莱托概率模型预测空白区剩余资源潜力前提下,以油气藏分布有序性理论为指导,确定南斜坡以岩性-构造油藏为主要勘探目标。并在构造、物源、沉积、储层精细解剖基础上,建立渤南洼陷南斜坡沙三段空白区多源多扇多期叠加的精细地质模型。同时开展成熟探区"9图1表"成藏条件统计分析,认为研究区沙三段油气成藏模式具有随砂迁移、逐层分布、断层封堵、优相富集的特点。通过成功与失利探井正反对比,明确储层不发育、断层不封堵、含油高度预测不准3大失利原因是导致储量难以上报的因素,并开展针对性攻关,建立空白区储层精细建模、断层封堵评价、圈闭含油高度预测的关键技术。通过成藏要素的定量刻画,优选有利圈闭,并针对重点目标开展勘探部署,取得良好勘探效果。

Method for exploration target optimization in blank region of main oil-bearing beds in mature exploration area-A case study of Es3 Member in south slope,Bonan Subsag

The exploration of Jiyang Depression has reached in mature or over-mature stage.In view of the increasing of re serve blank area of main oil-bearing beds in mature exploration area,a method,which is suitable for optimizing petroleum exploration target in the main oil-bearing beds of mature exploration area,is established focusing on the Es3 Member in south slope,Bonan Subsag being defined as“seven-step processes”.This method is used to predict the potential of remain ing resources in the blank area under the guidance of the“Pareto Geological Probability Model”,and the lithologic structur al reservoir is determined as the main exploration target in the south slope according to“Oil and Gas Reservoirs Orderly Distribution”theory.On the basis of fine dissection on“structure,provenance,sedimentation and reservoir”,a fine geologi cal model with multi-source,multi-fan and multi-stage superimposition in blank area is established for the Es3 Member in the south slope,Bonan Subsag.The statistical analysis of reservoir-forming conditions in“9 pictures and 1 table”of mature exploration area is carried out at the same time.The reservoir-forming characteristics of the Es3 Member in the south slope,Bonan Subsag are sorted out,including migration with sand,layer-by-layer distribution,fault sealing,and enrichment with excellent facies.Through comparison of the“positive-negative ratio”between successful and unsuccessful exploration wells,the three major failure reasons for undeterminable reserves are undeveloped reservoir,unsealed fault,and inaccurate oil height.Targeted research is carried out to establish the key technologies in reserve blank area,including the fine reser voir modeling,fault sealing evaluation and prediction of trap oil-bearing height.Through quantitative characterization of reservoir-forming factors,favorable traps are optimized,and exploration deployment is carried out for key targets,and good exploration results are achieved.