A Study On Liu Qu4+5Reservoir Of Chuan Kou Oilfield Drainage Water Flow Characteristics

Chuankou oilfield is located in Chuankou town-ship, Baota District, Yanan County in Shanxi province,10-15km away from Baota District, Yanan County, east to Yaodian oilfield and south to Nanniwan oilfield. Liuqu Area is located in the southwest of Chuankou oilfield. Generally, seepage characteristics of fluid in low permeability, extra-low permeability reservoir are greatly different from that in moderate permeability, high permeable reservoir. Most of reservoirs in Ordos Basin are with low permeability or super-low permeability. So, it is of great importance to study and understand the reservoir void structure, oil micro-flow characteristics and seepage rules in low permeability, extra-low permeability reservoir. By many methods, such as Grain Size analysis, Casting Slice technique, conventional Mercury Penetration experiments, the constant-rate Mercury Penetration experiments and relative permeability analysis, and regional comparison, this paper does a detailed research on reservoir void structure seepage characteristics of reservoir chang4+5in Liuqu Area, Chuankou oilfield. It comes to some conclusions as follow.(1) Since the fine pore and throats, Liuqu Area Reservoir Chang4+5ultra-low permeability reservoir fluid reservoir in the process of being rock seepage hole wall and the fluid solid, liquid interface on the strong role of surface molecular forces, seepage pressure exists start poor, the start pressure range of1-10MPa, under normal circumstances6MPa.(2) low permeability reservoir parameters such as porosity and permeability is a function of effective stress formation, formation fluid inflow or outflow is a variable coefficient nonlinear solid coupling seepage flow process. Drainage study found that Liuqu Area Reservoir Chang4+5core matrix micro-cracks porosity, permeability increased with the increase of net pressure decrease, fluid-structure interaction effect is obvious.(3) By Liuqu Area Reservoir Chang4+5core drains for water flooding experiment, when the porous medium oil saturation is low, the continuous oil column often occurs card off, resulting in a large number of oil droplets, Jamin effect of a very prominent.(4) Self-priming experiments confirmed that a large number of models, Liuqu Area Reservoir Chang4+5drainage showed weak hydrophilic characteristics, there is a (5) In summary, the low-permeability reservoirs have started a large pressure difference, the driving pressure gradient large, Jamin effect injuries and other characteristics, such flooding reservoir pressure gradient large, reaching12.25MPa/100m.