摘要
柴达木盆地西部跃进二号构造下干柴沟组上段(E32)发育了湖相生物礁,主要有由基质支撑的藻叠层石礁和骨架生物礁2种类型。生物礁孔隙非常发育,是该区的优质储层。对跃西4井生物礁储层物性进行了重点测试,其孔隙度平均26.1%,渗透率平均达97.2×10-3μm2。孔隙类型主要有:粒间孔隙、骨架孔隙、体腔孔隙、粒内孔隙以及溶孔和溶洞。生物礁的地震响应和测井曲线特征明显,结合岩心和录井资料可以有效地识别和预测生物礁。生物礁的形成除了生物因素以外,还会受到古气候、古纬度、古水动力、古水介质条件以及陆源碎屑等的影响;同时,它的发育受大地构造、湖底地形的控制。生物礁的发现对于青海油田油气勘探与开发具重要的现实意义。
In the Yuejin-2 structure of the western Qaidam basin, Palaeogene organic reefs are developed in the lower member of the lower Ganchaigou Formation （E3^2）, and two types of reefs are recognized, matrix-supported reefs （stromatolites）and skeleton-supported reefs （frame reefs）. The reefs have complex pores, such as interparticle pores, skeletal pores, coelomic pores, intraparticle pores and corroded cavities, which are excellent reservoirs in the study area. Reservoir characteristics of the reefs in the Yuexi-4 well are thoroughly tested whose average porosity is 26.1% and average permeability is 97.2× 10^-3 um^2. The organic reefs show distinct characteristics of seismic response and well logs, so the reefs may be identified and predicted according to their geophysical characteristics. Besides biotic factors, their development is affected by palaeoclimate, palaeolatitude, palaeo-hydropower, palaeo-aqueous media and terrigenous clasts. On the other hand, their development is controlled by tectonic structure and landform of the lakebed. The discovery of Palaeogene organic reefs in the Qaidam basin is of important practical significance for the exploration and development of the Qinghai Oilfield.
出处
《地质论评》
CAS
CSCD
北大核心
2005年第6期656-664,i0001-i0002,共11页
Geological Review
基金
中国石油天然气集团公司创新基金项目(编号2002F70108)
高校博士点基金(编号20030425008)资助成果
