Study On The Dynamic And Reasonable Intermittent Working System Of Low And Low Efficiency Oil Well

In recent years, the exploitation of low permeability reserves has become an important growth point of China’s oil and gas production. X oil field is the typical "Three Low Character" reservoir. Due to the complicated geological structure and, the development of X oil field is very difficult, not only the well yield but also the pump efficiency is very low. Because of the seriously gas affection, the phenomenon of "dry pumping" is often seen in low production and inefficient oil wells. In order to reduce influence of gas, avoid the phenomenon of "dry pumping" and improve the efficiency of the pump, reduce the mechanical wear and save energy, intermittent oil production is an effective and economic measures.In this paper, taking the low production and inefficient oil wells of X oil field 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 inflows and outflows dynamic models of low permeability reserves, studied the method of reasonable intermittent work system.(1)By analyzing the reservoir,fluid flow, production performance as well as the well test interpretation analyzing of the X oil field, getting a full understanding of the reservoir and production characteristics of the region.(2)According to the actual situation of X oil field, considering the effect of starting pressure gradient and stress sensitivity. The steady state flow of oil-gas-water three-phase is studied, the three-phase flow equation of IPR is derived, and a calculation software is prepared, then examples are calculated and analyzed.(3)Using the Principle of material balance, studied the calculation method of the time of open and close well when intermittent oil production. Summarized the general law of the relationship between the pump efficiency and submergence. And combined with the actual data of X reservoir, summed up the empirical relationship pump efficiency and submergence of X reservoir, then examples are analyzed.The concept of minimum reasonable submergence and highest fluid level of intermittent oil production is proposed. The fluid level range of intermittent oil production is determined. And this paper chosed three wells as the exanples, formulated their work system of intermittent oil production.This study provides a theoretical and applied basic for the analysis of inflows and outflows dynamic models of low production and inefficient oil wells of low permeability reserves and the determination of reasonable working system of intermittent oil production.