The article covers the record of dual completion application in Vietsovpetro JV wells including the specifics of the developed areas (GOR, gas condensate content, reservoir pressures and temperatures, composition of produced and injected fluids, presence of aggressive impurities, sand, paraffins, mineral salts and etc.). It also describes the main types and amount of dual completion systems applied from 2014 to the present day, functional capabilities of the equipment, and standard design of dual completion systems deployed in Vietsovpetro JV. The article comprises the analysis of dual completion efficiency and main geological factors which complicate the dual production. Dual completion allows: enhance oil recovery and existing production rates by developing the low permeability zones and layers; increase sweep efficiency and intensity of multilayered fields development by selective inclusion of separate layers with various permeability; greatly reduce the capital expenditures on well construction (particularly true to offshore fields); optimize sampling and injection by well log; prolong the commercial time of field development and operation; control over oil production from each zone and agent injection to every layer, etc. The paper includes the main application criteria and requirements to equipping the dual completion systems for Vietsovpetro JV fields; brief statistics of failure rates while adjusting the assemblies equipped with dual completion systems by wireline techniques, as well as during workovers for retrieving the downhole equipment with dual completions. The article covers the main complicating factors which lead to inefficient operation of the downhole equipment with dual completion systems, analysis of lessons-learned, main problems and applied solutions, as well as potential lines of approach for complications which may occur during operation of wells equipped with dual completion systems. The authors designate the perspectives for improving the dual completion systems for Vietsovpetro fields, considering adaptation to subsurface conditions, search and pilot tests of new systems, including lower completions and stepwise transition to intellectualization.
