Rock mechanics of Chang7 reservoir in Wuqi Oilfield,Ordos Basin
Significant breakthroughs have been made in the exploration of tight oil in Chang7,Wuqi Oilfield.Twenty-three detailed exploratory wells have been tested,and industrial oil flows have been obtained.The area has not yet been developed on a large scale,and there are few reference data for reservoir stimulation,especially the mechanical characteristics of reservoir rocks that need to be tested and analyzed.Conventional and sealed core samples from multiple exploratory wells were used,and instruments and techniques such as scanning electron microscopy,fluorescence thin sections,cast thin sections,X-ray diffraction,rock hardness tester,tensile strength testing device,uniaxial and triaxial strength testing device,and Kaiser effect acoustic emission method were employed to conduct reservoir characteristics and rock mechanics experiments.The results showed that:1)The reservoir with low porosity and permeability is tight;most pores are intergranular and dissolved feldspar pores;2)The reservoir rock is lipophilic,with weak rate and acid sensitivity,and medium-weak water,salinity,and alkali sensitivity;3)The rock hardness category is hard,and the tensile strength of the interbed of sandstone and mudstone is greater than that of sandstone;4)The axial and radial pressures increase as the confining pressure increases,and the reservoir is dominated by horizontal principal stress.The experimental results have important reference significance for reservoir reserve calculation,development plan preparation,and volume fracturing.
万方数据
维普
