Study On The Dynamic And Reasonable Working System Of Open Well Inflow In Low Permeability Reservoirs In Huaying Oilfield

In recent years, the proportion of low permeability reserves founded in newly discovered reserves is larger and larger. Low permeability reserves have become the most important foundation energy to increase our country’s production. Changqing oil field is located in Ordos basin,it is the "Three Low Character" reservoir which is rare in the world. Due to the complicated geological structure, the development of Changqing oil field is very difficult, not only the well yield but also the pump efficiency is very low. Operating oil pump intermittenttly and determining the reasonable working system for inefficient wells can effectively avoid the phenomenon of "dry pumping " and improve the efficiency of the pump, reduce the mechanical wear and save energy, ultimately achieve the target of energy conservation while the efficiency don’t drop. Intermittent oil production has become the effective measures to improve the economic benefits.In this paper, taking the White153well area which is ultra-low permeability in Huaqing region as the research object. By the integrated use of the means and methods of geology, fluid mechanics in porous medium, reservoir engineering, production engineering, and other multi-disciplinary cross-linking, establish a inflow performance model of intermittent producing well in low permeability reservoirs,define the reasonable working system.(1) by analyzing the reservoir,fluid flow, production performance as well as the well test interpretation analyzing of the White153well area in China Qing oil field,getting a full understanding of the reservoir and production characteristics of the regio n.(2) According to the actual situation of White153well area, Considering the effect of start-up pressure gradient and stress sensitivity on the seepage in formation.the IPR equation of single-phase,oil-water two-phase, as well as oil and gas two-phase in the steady state flow conditions is established,then one example is calculated and analyzed.(3) Using the Principle of material balance to study the change law between the liquid surface in wellbore and time, and analyze the relationship of bottomhole pressure and producing liquid level,as well as time.(4) Combined with the specific conditions in White153well area,the main influence factors on pump efficiency of intermittent production wells are analyzed. The relationgship of moisture content, liquid production,submergence depth,and pump efficiency is given. This will provide a basis for the determination of a reasonable working system for intermittent production well.(5) Combined with the characteristic of inflow performance relationship in low permeability reservoir, the change law of liquid level in wellbore and the pump efficiency analysis,establishing a coupling model of formation and wellbore on the basis of full understanding of the relationship between the supply capacity of formation fluid and pump suction capacity.then Using the compiled program to determine the resonable working system of intermittent production well.This study provides a theoretical and applied basic for the analysis of inflow performance and the determination of reasonable working system.