珠江口盆地陆丰凹陷古近系多动力-多期次-多要素复合成藏区定量预测与评价

Quantitative Prediction and Evaluation of Paleogene Favorable Hydrocarbon Accumulation Areas with Multi-Dynamic-Stage-Factor Combination in Lufeng Sag,PearlRiver Mouth Basin

珠江口盆地陆丰凹陷古近系油气成藏受多种动力多种要素联合控制,因此不能完全依照经典的浮力成藏理论预测有利成藏区带.通过剖析研究区已经发现的油气藏揭示出三种动力对油气成藏起到了关键作用,包括低位能(背斜类油气藏)、低压能(断块类油气藏)、低界面能(岩性地层类油气藏);在每一种动力作用下,油气成藏受到有效烃源层、优相储层、区域盖层、低势区带4个功能要素及其时空组合的控制.通过建立多动力-多要素复合成藏模式,对陆丰凹陷古近系4个目的层有利成藏区带进行了预测评价,优选出10个最有利目标,为研究区油气深化勘探和钻探目标优选提供了科学依据.

The Paleogene oil and gas accumulation in Lufeng Sag of the Pearl River Mouth Basin is jointly controlled by a variety of dynamic factors,so the favorable reservoir forming area can not be predicted completely according to the classical buoyancy reservoir forming theory.By analyzing the discovered oil and gas reservoirs in the study area,in this paper it reveals that three driving forces play a key role in oil and gas accumulation,including low-level energy(anticline oil and gas reservoir),low-pressure energy(fault block oil and gas reservoir) and low interface energy(lithologic stratigraphic oil and gas reservoir).Under each dynamic action,oil and gas accumulation is controlled by four functional elements and their temporal and spatial combination:effective source rock,excellent facies reservoir,regional cap rock and low potential zone.By establishing a multi-dynamicfactor composite reservoir forming model,the favorable reservoir forming zones of four target layers in Lufeng Sag are predicted and evaluated,and 10 most favorable targets are selected,which provides a scientific basis for deepening oil and gas exploration and optimizing drilling targets in the study area.