江汉蚌湖含油系统油气分布及潜力

潜江凹陷蚌湖向斜是下第三系潜江组的沉积中心 ,是江汉盆地油气最富集的生烃中心。蚌湖含油系统边界条件清晰 ,研究范围 470km2 内勘探程度高 ,探井密度达到 1 10 4口 /km2 。已发现王场、钟市、广华等 13个油田 ,探明石油地质储量 6 848× 10 4 t,占江汉盆地探明储量的 5 9 7%。根据潜江组盐系地层的特点 ,陆相含油盆地源控论和油气在生油凹陷呈放射状往四周运移的观点 ,将蚌湖含油系统划分为广华区块、王场区块和西坡区块。根据各区块的油气分布特点、勘探程度、目前认识及地质条件进行油气勘探潜力分析 ,作出了区块类比的经验性预测。潜力预测以勘探程度最高的广华区块为基础 ,王场区块与广华区块类比 ,西坡区块与王场区块类比。潜力分析结果 :蚌湖含油系统剩余可探明石油地质储量的期望值为 (2 494～ 3 977)× 10 4 t,期望中值为 3 2 35× 10 4

Distribution of Hydrocarbons from Banghu Petroleum System and Prospecting Potential of Jianghan Basin

Banghu syncline in the Qianjiang sag is a depocenter of Paleogene Qianjiang Formation, and is the richest hydrocarbon generation center in Jianghan Basin. The Banghu petroleum system has clear boundaries, and high degree of prospecting within 470 km 2 studied area,having an exploration well density up to 1.104 well per km 2. There have been 13 oilfields discovered in the syncline, including Wangchang, Zhongshi, Guanghua Oilfields etc. . The proven OOIP of the Banghu syncline is 6 848x10 4 t,accounting for 59. 7% of that of the Jianghan Basin. The Banghu petroleum system is divided into Guanghua, Wangchang and West -Slope blocks,based on the point of views as following: characters of salt sequences of Qianjiang For-mation, Source Control Theory about non - marine oil basin, hydrocarbons migrating radially towards the oil - generation sag margins. Analysis of oil and gas prospecting potential for these blocks is on the basis of oil and gas distribution, degree of prospecting of each block, current knowledge and block anologue empirical prediction derived from geological correlations. Potential prediction is made on the basis of the Guanghua block, having the highest degree of prospecting, analogy between Wangchang and Guanghua blocks, analogy between West- Slope and Wangchang blocks. The analysis conclusion is that the expected value of possibly proven remaining OOIP of Banghu sag is 24.94 ~ 39. 77 million tons, and the median of that is 32. 35million tons.