Tight Oil Reservoir And Source Rock Logging Evaluation Of The Lower Member, Upper Ganchaigou Formation, Zhahaquan Area

The exploration and development of tight oil has become a new research hotspot in the field of global oil and gas resources, in addition to achieve great success in North America, continental facies basin in China was also found considerable resources.In recent years, Zahaquan area, in the southwest Qaidam basin, was found tight oil reservoirs of the lower member, upper Ganchaigou formation in tertiary and got industrial oil flow in drilling. But according to complex geological situation and low degree of reservoir recognition in the region, it encountered many difficulties in the subsequent exploration, so it is in urgent need of building effective logging evaluation method for the tight oil reservoir in this region.According to core observation, analysis and testing, and producing test production of dynamic data analysis, grasp the geological characteristics of the main reservoir and hydrocarbon source rocks in the study area. Research shows that the lithology of tight reservoirs in Zahaquan area is mainly sandstone, siltstone, shale and siltstone, silty mudstone, marl, mudstone and minor interbedded thin, fine, siltstone sandstone as the main reservoir, mudstone marl as the main source rocks, sandstone have a complex mineral composition, and vertical changes quickly; pore types in the study area is mainly primary residual intergranular pores, and a little intragranular dissolution porosity, intercrystal pore and paste grain seam; the organic matter abundance of hydrocarbon source rock is medium to high, organic matter type is well, and lied in the higher stages of maturity.On this basis, studying of logging response characteristics of reservoir and source rocks picking logging sensitive parameters, using overlapping diagram, cross-plot method, multi mineral model method, multiple linear regression, muddy sandstone water saturation formulas and other methods we established log interpretation method of the key parameters of the reservoir and source rock, and integrate interpretated important wells, using those models. Combined with the oil test results, summarized the main relationship of source rock-reservoir collocation types and its relationship with the oil reservoir in this area, shows that there are four sources relationship of source rock-reservoir collocation, influence reservoir oiliness:the "high-quality source rocks and high-quality reservoir" usually form a high-yield oil layer; "high-quality source rocks and poor reservoir" generally form poor oil or dry layer; "poor source rock and quality reservoir" generally form the water layer; source rocks and reservoir conditions all poor are generally form a dry layer or water layer.