In order to maximize oil recovery from shallow and thin reservoirs, Extended Reach (ER) producer and injector wells are becoming common in the Russian Sector of the Caspian Sea. In recent years, Korchagina wells have illustrated the difficulty of achieving effective production along lengthy reservoirs with traditional completion methods. The objective of this paper is to share practical experience gained during deployment of the most advanced Intelligent Completion Systems (ICS) in ER wells. The paper covers detailed analysis, challenges encountered, solutions implemented, and lessons-learned while completing multi-zone wells.
Hydraulically actuated ICS installations on the Korchagina field began in 2014 and continues to date, exceeding expectations for oil recovery. The paper discusses the deployment of recent record-breaking fully-electrically operated ICS in complex 3-D ER wells. Also, the paper covers the multi-disciplinary approach in optimizing drilling practices and techniques, which allowed landing of the longest 10¾" horizontal production casing at 3873m on Well A, as well as the deployment of the longest combined 7" × 5½" liner with wire-wrapped screens and a total length of 3447m, and the longest intelligent completion system with a total length of 3083m, on Well B in the Caspian Sea. The previous world record was comfortably surpassed, with deployment of the ICS inside the 7" liner to a depth of 5187m.
The detailed torque and drag (T&D) modelling of the liner and completion deployment was performed both at the planning and execution stages to ensure that there was sufficient surface weight and torque available. Proprietary Drilling Engineering software was used to derive the expected T&D, extract expected running conditions from previously executed wells, and predict potential challenges. It was also applied during the actual deployment with real-time data being extensively processed and analyzed. The slightly conservative modelling enabled identification of liner and ICS equipment that required modifications and helped to enhance running procedures. Further, the strategic approach to the placement of both swellable open hole packers for the liner, based on caliper and LWD data, and hydraulically-set inner-string isolation packers, is described.
The design and planning of the complete cycle of well construction, including deployment of the intelligent completion system, resulted in flawless completion of the wells with a successful field application and delivered a significant oil recovery increase on the field.