Many fields developing by Oil and Gas Production Department Nizhnesortymsckheft are currently characterized by an increase in the share of hard-to-recover reserves. These reserves are concentrated in low-productivity strata, strata with unfavorable conditions of occurrence of oil or containing oil with abnormal physical and chemical properties. The number of oil wells, the operation of which is unprofitable due to low production rate, is increasing every year with the change in the oil reserves structure. In the future the number of marginal wells will grow rapidly.
To solve the problems, associated with the operation of marginal well stock, the works on implementation and qualitative selection of submersible equipment, testing various kinds of pumps and preventive measures with application different scale inhibitors and hydrochloric acid treatments are carried out under the supervision of the Surgutneftegas OAO Production Division on the oil recovery and reservoir pressure maintaining at Nizhnesortymsckheft’ fields.
The operation of marginal wells, equipped with electric submersible pump units, is analyzed. The description of the factors, that complicate their work, is given. The features of the periodic operation of mechanized well stock are considered. Results of screw pumps EOVNB5-6-2000 tests that were carried out in 2014-2015 at the well stock with complicated operating conditions. The data, obtained at the realization of the program of pilot projects on the carrying out of short-term periodic operation of wells, equipped with electric submersible pump units, at the Ai-Pimskoye field, are presented. It was noted, that one of the advantages of short-term intermittent operation is the ability to change the pumping rate without lift and unit size change only by varying the pumping and accumulation time ratio. The pump units were equipped with submersible electric motors with thermomanometric systems in order to timely control and operational decision-making on the selection of a harmonized operation regime.
It is concluded, that the use of short-term intermittent operation mode of electric submersible pump units operation in conjunction with redundant check valve KOSh-73 and soft start control system is currently one of the most promising ways of oil recovery from low-permeability reservoirs and objects with large compartmentalization.
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