Process of Selecting and Testing Well Lower Completion Methods for Russkoe Field Poorly Consolidated Rock Conditions

摘要

The Russkoe gas and oil field was discovered in 1968. No attempts to begin its commercial operation in the former USSR were and have been successful till the present time. The issue of economically attractive development of the Russkoe field is very urgent for TNK-BP since the field is a strategic oil asset to replenish company reserves. The field is located in the Arctic zone, in the north of the Tyumen Oblast, Russian Federation. Russkoe reserves are hard to recover, and the expected oil recovery factor is 14-15%. The main pay zone, PK 1-7, consists of unconsolidated poorly cemented sandstones with a high pelite fraction content. The reservoir is saturated with highly viscous oil (19 API), and low reservoir temperature (23°С) is predominant. Horizontal well profiles (over 500 m) are currently considered to be the most feasible ones from the economic point of view. The field is located in a hard-to-reach region with difficult logistics. With these conditions in view, correct selection of completion systems for sand control or containment is critical for assuring profitable operation of this asset from the point of view of maintaining well productivity, artificial lift and surface equipment loading. This article describes the TNK-BP process and experience in selecting the lower completion systems intended to suppress reservoir sand production in the Russkoe field. Different lower completion systems were tested during the pilot operations in 2006 – 2010. To reduce uncertainty, a set of laboratory tests of completion systems produced by a number of Russian and foreign manufacturers were conducted using the Russkoe field well fluid and core samples. The experience of leading servicing companies as well as experience of developing similar fields in the world was also taken into account. The article discusses in detail the approach chosen, decisions taken, current results, and lessons learned.