Abstract

Large inactive well stock is one of the factors complicating current Russian oil field development process. As per 1 January 2008, the Russian Federation IWS amounted to over 26000 oil wells. Long-continued inactivity of a large well number reduces potential of development optimization and oil recovery enhancement methods, deteriorates production and economic performance, increases environmental impact risks.

IWS re-activation requires complex well servicing involving water isolation, fishing, sidetracking etc. Therefore, idle stock reactivation efficiency, as a rule, is lower than that of active well interventions. In these conditions particular emphasis is placed on selection of methodology for dealing with IWS, which considers retention of the project development system, achievement of maximum oil recovery factor and improvement of the field development cost-performance ratio.

A comprehensive TNK-BP Idle Well Stock Reactivation Program was developed within the frame of Company's strategy, to reach the following objectives:

  • by end of 2013, to reduce IWS to the amount close to the standard (10%);

  • complete license obligations fulfillment in the part of drilled well-stock utilization, including solutions of the approved project process documentation;

  • application of advanced technology to re-activate idle wells and enhance their performance.

The article considers results of comprehensive Idle Well Stock Reactivation Program implementation, describes examples of idle well reactivation and design technology / project development system recovery technology implementation, and identifies ways to improve performance. It is demonstrated that even in conditions of high depletion ratio and extremely high watercut, substantiated use of modern technologies allows to guarantee efficient production of remaining oil reserves.

Introduction

Large inactive well stock was a major concern which TNK-BP had to face at the moment of Company's origination in 2003. IWS percentage grew steadily since 1990 and reached as high as 41% of development well's number. Significant increase of IWS by the beginning of the XXI century was typical for many Russian oil companies and was attributed to both internal (the 90s' Russian economy formation challenges) and external (worldwide oil crisis, low oil price) conditions.

It is evident that extended well inactivity negatively affects field development efficiency and increases environmental impact risks. For this reason, work on comprehensive Idle Well Stock Reactivation Program was organized at the very beginning of TNK-BP's activities. The Program was formed and submitted for approval to RF Ministry of Natural Resources in 2006. After discussion, the program was approved by the Ministry and recommended for introduction.

The program provides for:

  • systematic IWS reactivation in 2006–2012 to reach a level close to the standard by 2013 (10% of the operating well stock);

  • annual carrying out of 3500–4000 operations (interventions) in idle wells;

  • decreasing pace of transferring wells from active to inactive stock, also at the expense of planned increase of downhole pump equipment's time between failures;

  • timely abandonment of wells which completed their project function;

  • use of modern technology for idle well-stock re-activation, efficiency enhancement and oil extraction rate increase (sidetracking, horizontal kickoffs, drilling of backup wells from mobile rigs, multi-lateral drilling etc).

This content is only available via PDF.
You can access this article if you purchase or spend a download.