Improvement of Drilling Technology for the Yarega Heavy Oil Field Development By SAGD Method with Counter Producing and Injecting Wells

Abstract

Abstract Utilization of thermal production technologies in Yarega heavy oil field exemplifies a large-scale experiment of paramount importance for future development of oil industry, science, economics and technology. This paper presents a review of over than 75 year history of production technological development in Yarega heavy oil field. It shows that Russia pioneered and advanced in time in heavy oil and bitumen production, the world resources of which greatly exceed the light oil resources. The authors emphasize the LUKOIL-Komi experience, obtained during SAGD technology introduction in Yarega heavy oil field and drilling long horizontals (up to 1000 m) at shallow depths (200-210 m). SAGD technology was an alternative to oil mining, that had been used their since 1939. In 2006 three pairs of horizontals have been drilled in pilot testing area. Steam injectors were 5 m above producers, and average length of horizontal sections was about 300 m with total length of 610 m. In 2011-2012 another five pairs of producers and steam injectors have been drilled from two different clusters located 1400 m apart. Left and right pairs were azimuthally deviated. The problem in drilling of such wells was that the pay zone TVD was up to 220 m, and, therefore, the dog leg severity was 3.50° per 10 m. And the event of azimuth changes it increased up to 4° per 10 m and more. This resulted in problems with pushing BHA and casing, and also with placing fiber optic cable on the outer casing walls. In 2013 started the opposing wells drilling using the rack type rigs with 45-72° spudding angle, which decreased the dog leg severity and provided the longer horizontal sections. The paper provides a comparative analysis of advantages and disadvantages of vertical rigs and rack type rigs based on projected and actual field data.