塔里木盆地哈拉哈塘地区油气藏特征及主控因素——以哈11井区为例

Analysis on reservoir characteristics and main controlling factors in Halahatang area, Tarim Basin: a case study of Ha11 well block

哈拉哈塘地区是塔里木盆地北部重要的油气勘探区。随着勘探的不断深入,大量的油气资源被发现,但也出现油水分布关系复杂、油气藏特征及主控因素不明确等问题,严重制约了研究区的油气勘探开发。以哈拉哈塘油田哈11井区为例,对其油气藏特征及主控因素进行研究。哈11井区分为哈11和哈12共2个缝洞带,哈11缝洞带整体上出油,钻井成功率高,高产井较多,而哈12缝洞带钻井成功率较低,低产井和水井所占比例较大。对研究区的断层、构造、地层、流体性质变化特征以及储层类型等分析表明,其油气成藏受断层、构造位置和储层类型控制。虽然哈11和哈12缝洞带具有相似的构造、地层和流体性质变化特征,油气相态均为未饱和油藏;但哈11缝洞带主要受控于北西向早—中加里东期大型走滑断层及其伴生小型断层,而哈12缝洞带主要受控于北东向早—中加里东期大型走滑断层及其伴生小型断层,且构造位置和储层类型也对油气具有控制作用。

Halahatang area is located in the northern Tarim Basin that is an important oil and gas exploration area. With the further ex-ploration, plenty of oil and gas resources are discovered, but the complexity of distribution of oil and water, and the uncertainty of thereservoir characteristics and the main control factors seriously restricted the oil and gas exploration and development in the study area.Based on the analysis of Ha11 well block in Halahatang oilfield, we study the reservoir characteristics and main controlling factors inHalahatang area. It can be divided into two fracture-cavity belts in Ha11 well block: the Ha11 fracture-cavity belt and Ha12 fracture-cavity belt. The Ha11 fracture-cavity belt is overall oil, and the drilling success rate is high with more efficient wells. But the Ha12fracture-cavity belt is low in drilling success rate, and has a larger proportion of failure wells with abundant water. Analysis of the struc-ture characteristics, formation characteristics, phase characteristics, fluid property variation characteristics, faults and reservoir types ofthe study area, we summarize the reasons accounting for the oil-water distribution differences between these 2 fracture-cavity belts instudy area. The results show that the Ha11 fracture-cavity belt and the Ha12 fracture-cavity belt are similar in structure characteristic,formation characteristics and fluid property variation characteristics, and are all the same unsaturated oil reservoirs. But through thecomparative analysis, the Ha11 fracture-cavity belt is mainly controlled by NW early-middle Caledonian large strike-slips and itssmall auxiliary faults. The Ha12 fracture-cavity belt is mainly controlled by NE early-middle Caledonian large strike-slips and itssmall auxiliary faults. So, that is why Ha11 well block was divided into two fracture-cavity belts, two oil-water systems. In addition, therelative level of structure and the reservoir types are also an important reason to cause these two fracture-cavity belts with different oil-waterdistributions.