欢喜岭油田南部沙一-二段缓坡型扇三角洲沉积特征及演变规律

Sedimentary Character and Evolutional Rule of Slow Slope Fan Delta of the First and Second Members of Shahejie Formation in the South of Huanxiling Oilfield

欢喜岭油田位于辽河坳陷西部凹陷的南部,沙一-二段期发育缓坡型扇三角洲。通过对岩心、录井资料分析,认为该区所发育的缓坡型扇三角洲具有细粒沉积物含量高、牵引流沉积较发育和扇三角洲前缘亚相发育的特征;同时通过对研究区不同时期沉积相展布特征的分析,对扇三角洲的演变特征进行了总结,得出沙一-二段期间扇三角洲前积能力逐渐减弱,沉积物粒度逐渐变细,其长轴方向也由北西-南东向向南北向转变。在此基础之上对有利砂体分布进行了预测;认为在锦130井、锦132井以南及双203井与锦307井附近为有利砂体较集中发育区,可作为油气勘探的重点区带。

Huanxiling Oilfield was situated in the south of West Depression of Liaohe Sag. The slow slope fan delta was developed in period of the first and second Members of Shahejie formation. Through the core and logging data analysis, it was found that the sediments had a high percentage of fine grained sediments and traction current deposits, also its delta front subfacies was more developed. At the same time, through analysis of sedimentary facies distribution of different stages, it was found that during the first and second Members of Shahejie formation the prograding ability of fan delta was gradually weakened and the deposition included more and more fine grained sediments. Furthermore, its long axis direction changed from the Northwest-Southeast to North-south. Based on these, the distribution of beneficial sand body is predicted. It is considered that the south of Well Jin130 and Well Jin132 and around Well Shuang 203 and Well Jin307 are more beneficial sand body distributions, it can be beneficial region in oil and gas exploration.