叙利亚Oudeh油田上白垩统Shiranish组碳酸盐岩储层特征及成因模式

Characteristics and Genesis Model of Upper Cretaceous Shiranish Carbonate Reservoir in Oudeh Oilfield,Syria

叙利亚东北Oudeh油田上白垩统Shiranish油藏储层为一套由孔隙性颗粒灰岩构成的碳酸盐岩缓坡沉积,其构造背景总体上为北西高、东南低,并被近东西和近南北走向的两组断层分割成若干断块,其中近南北走向的几条大断层为同生断层,是油田内的主控断层。同生断裂作用形成的古地形高差对沉积和成岩作用有一定的控制作用,从而控制了优质储层的形成及分布。粗粒的颗粒灰岩沉积和有利的成岩作用带主要分布在靠近同生断层高部位一侧的条带内,导致油藏呈近南北向条带状分布。据此建立了Shiranish储层成因模式,该模式为预测优质储层分布及油田开发的井位调整和部署提供了决策依据。

The Oudeh Oilfield is located at the northeast of Syria.The upper Cretaceous Shiranish reservoir in this oilfield is mainly comprised of porous grainstone/packstone in a carbonate ramp.Under a tectonic setting of being high northwestwards and low southeastwards,the oilfield is cut into several fault blocks by approximately N-S trending and E-W trending faults,among which several major N-S trending ones are growth faults,which are also the dominant faults in this oilfield.Height difference of paleotopography caused by contemporaneous faulting has control over sedimentation and diagenesis in some extent therefore it controls the formation and distribution of excellent reservoir.Coarse-grained grainstone/packstone and favorable zone of digenesis,such as meteoric water leaching and dolomitization,mainly distribute in a banded zone that is close to one side of growth faults,which results in nearly S-N directional zonal distribution of the reservoir.Based on the above-mentioned study,a genesis model of Shiranish reservoir is established and illustrated.This model provides good reference and guidance for prediction of excellent reservoirs and exploration of similar reservoirs.