Reservoir Log Evaluation Of Xiashihezi Formation In Hangjinqi Area Of The Northern Ordos Basin

Structural position of Hangjinqi area located Yimeng uplift of northern Ordos Basin and the transition zone between Yimeng uplift area and Shanbei slope. Currently, there are less drilling wells in the region, the degree of exploration is still relatively low, the depth of reservoir is a larger, typical of low porosity, low permeability reservoir, combined effects of surface conditions, the lack of seismic data, comprehensive study of relatively is weak, so full use of geological data and reservoir evaluation of logging information will be important means of reservoir cmprehensive evaluation in Hangjinqi area.In this thesis, the basis of previous research, using the logging, sedimentology, petroleum geology, the combination of integrated multi-disciplinary research methods to collect adequate test gas, logging, testing data of physical property analysis, which expand research of logging evaluation of Xiashihezi formation in the study area. To make research more scientific and practical, using comprehensive study method of macro-and microscopic, single well geological data and geological data, geological logging technology, to study development of formation, depositional system, reservoir distribution in Xiashihezi formation and to master characteristic of sedimentary facies and development of reservoir.Deposition system of Xiashihezi formations in Hangjinqi region are mainly make up of alluvial fan depositional system, river sedimentary system and braided delta system. Component maturity of sandstone reservoirs is high, maturity structure is low; Primary pores and secondary pores are both developed, but secondary porosity is the main; as low porosity and low permeability reservoir, the reservoir pore structure is complex.Based on detailed study of "four" relationship, and then identify lithology, calculate the key parameters of the reservoir, integrated discrimination gas. Studies have shown that the acoustic time and spontaneous potential curves overlap, which can be accurately identified and effective reservoir; After unification of the three-dimensional porosity curves, the sound waves and neutron porosity overlap, density and neutron porosity overlap, according to the magnitude difference between the curve, which quickly identify gas-bearing; the acoustic impedance/acoustic curve and sound wave reverse overlap, according to the difference between the curve apparent magnitude, to obviously identify gas. At the same time, the cross plot of DT and LLD, cross plot of DT and DEN can distinguish dry layer and gas layer. The cross plot of GR and LLD can distinguish water layer. Through the above work to establish reservoir parameters (clay content, physical properties, saturation) log interpretation model, the accuracy reaches the actual production log interpretation accuracy.Finally, base on comprehensive evaluation of gas gathering petroleum plays of H8 and H7 of Xiashihezi formation, show that there are gas exploration prospect in H8 and H7.