基于随机介质建模的生物礁储层评价方法探讨——以南海L盆地生物礁为例

Methodology for reef-shoal reservoir by the randon medium simulation

南海L盆地深水区,不仅有新近系生物礁发育的良好环境,更有生物礁油气藏形成的优越条件,是未来深水区勘探的重要领域.在生物礁储层评价、油气预测研究中,由于研究对象多为孔缝洞发育的细微储层结构,常规地震勘探多基于理想均匀介质或层状介质来研究储层结构,这显然容易忽略实际生物礁储层的局部非均质性对地震波响应特征和传播规律影响.本文以L盆地生物礁为例,在层序地层划分及沉积相分析双重约束下利用相对阻抗反演技术有效建立了生物礁储层框架模型,采用孔洞随机介质模拟技术对储层内部孔洞裂缝进行精细雕刻,建立能精细描述生物礁储层内强非均质性及孔缝洞物性特征的随机介质模型.最后通过正演模拟,定量地分析了盆地内生物礁储层的物性特征,从而进一步明确了盆地内寻找优质储层的方向,为勘探目标的寻找与优选提供科学的理论指导.

The further researches should be emphasized in the L basin of South China Sea, where the conditions of both Neogene reef development and reefal hydrocarbon accumulations are excellent,forming an important deep-water exploration realm in the future.In the research of reservoir prediction for reef carbonate,it＇s obviously easy to ignore the heterogeneity influenced on the response characteristics of seismic waves owing to studying on reservoir structure on the basis of layered medium or homogeneous medium in conventional seismic exploration,particularly,the research of object is the more subtle reservoir structure such as seam hole medium.Taking the L basin as an example,this paper effectively established reef reservoir framework model combined with high frequency sequence division and sedimentary facies analysis on the basis of relative impedance inversion technique.It is accurately described for the hole and crack medium using the hole random medium simulation technology,and the establishment of the random medium model can fine description of reef carbonate reservoir such as strong heterogeneity and cavern physical characteristics.To further clarify the direction of finding high quality reservoir in the reed basin,the aim is to provide a theoretic guide for searching and optimizing exploration targets.