准噶尔盆地莫索湾地区地层水研究

Study on formation water in Mosuowan area of the Jungger Basin

姜林 宋岩 查明 曲江秀 薄冬梅

Jiang Lin Song Yan Zha Ming Qu Jiangxiu Bo Dongmei

莫索湾地区地层水发育情况十分复杂,存在苏林分类的NaSO,NaHCO,MgCl和CaCl型水.在纵向上的两个压力系统中,下部高压层地层水发育为反向水化学沉积序列,上部常压层的水化学沉积序列在不同区域有所差异.结合研究区区域构造特征,通过对地层水水型、矿化度特征等的综合分析,认为莫索湾地区地层水处于NaHCO型水的水文地质体系中;CaCl型水来自于深部地层,通过断裂构造的沟通运移至目的层;而NaSO和MgCl型水是由较高矿化度CaCl型水与较低矿化度NaHCO型水混合而成的;盆5井区与盆参2井区地质条件的差异造成了两井区常压层水化学沉积序列的不同;而成岩作用和生烃作用造成了高压层的反向水化学沉积序列.

Mosuowan area has developed a rather complicated formation water including NaSO,NaHCO,MgCl and CaCl four types.There are two pressure systems in the vertical direction,of which the lower high-pressure system shows reverse hydrochemical depositional sequence,while the upper part with normal pressure system has a little different hydrochemical depositional sequences in different areas.Study on regional structure features of the area and analysis of formation water types and salinities show that formation water in Mosuowan area is within hydrogeologic system of NaHCO type.The CaCl-type formation water is sourced from the deep strata and migrates into the reservoir through faults,while the NaSO-and MgCl-type formation waters are mixtures of CaCl-type water of high salinity and NaHCO-type water of low salinity.The difference between the geological conditions in Peng-5 well-block and Pengcan-2 wellblock is the main cause of the different hydrochemical depositional sequences of the strata with normal pressure in these two wellblocks.Diagenesis and hydrocarbon generation are the reasons behind the reverse hydrochemical depositional sequences of the strata with high pressure.

10.11743/ogg20080111