Commercial Application of Dual Completion Technology

Abstract

Abstract TATNEFT’s fields are, for the most part, multilayered with two and more development targets, which makes dual completion technology an optimal reservoir management solution. The Company’s first dual completions date back to the 1960-ies, however, deficiency of oilfield hardware, especially, packers, as well as lack of production control equipment prevented commercialization of this technology. The last decade witnessed a revived interest to dual completions. TATNEFT has been successfully implementing dual completion technology since 2003. Different dual completion systems to meet different production conditions have been developed. Completions with one and two strings of tubing using sucker rod pumps have found wide application. The singletubing-string completion system is used to produce from two segregated productive zones isolated with a packer. Though the well stream is commingled, methods to determine production rates, water cut, and bottomhole pressure for each target are available. The two-tubing-string completion system has been known since 1950-ies, and in its present configuration includes the in-house dual-string wellhead equipment, parallel anchor, and M1-X production packer. For more prolific wells two different production systems based on combination of electric submersible and sucker rod pumps are used: with commingled and non-commingled production. Production options for high viscosity oil provide for progressing cavity pumps. Also, dual completion technologies for injection using one and two packers have been developed. By now, dual completion systems have been installed in more than 500 production and injection wells with incremental ultimate recovery exceeding one million tons of oil. Dual completion technology has proved its efficiency for increase and stabilization of the production level, and it is one of the priority investment projects of the Company. TATNEFT plans expanding scope of the technology application, development of new dual completion systems, and improvement of existing ones.