Abstract
References
Information
Axial loads in coiled tubing drilling (CTD) should be minimized and not be exceeded helical buckling loads in order to transmit weight to a bit efficiently and to prevent buckling and lock-up occurrence. These loads are determined by the geometries of well path and load conditions. Therefore, it is essential to consider these loads for optimizing a well path in CTD. In this paper, an optimal well path is designed to avoid helical buckling behaviors and to minimize axial loads along with the wellbore by employing constant curvature method and an analytical friction model instead of designers’ experience or judgment. In the calculated well path, there is no section of sudden changes in axial and buckling loads where helical buckling can occur easily with slight increments of axial loads. Accordingly, the proposed method can be used more effectively to optimize well path in horizontal drilling where heavy loads are exerted on the drillstrings.
코일튜빙을 이용한 시추작업에서 시추관 내의 효과적인 하중전달과 버클링 현상 그리고 시추관 락업(rock-up)을 방지하기 위하여 시추관 하중은 최소화되어야 한다. 분포하중과 버클링 임계하중은 시추궤도 형태에 따라 크기가 결정되기 때문에 시추궤도 설계과정에서 이에 대한 고려가 선행되어야 한다. 본 연구에서는 하중분포모델을 이용하여 얻어진 각 지점에서의 분포하중과 버클링 임계하중을 제약조건으로 설정한 시추궤도설계 최적화 기법을 제안한다. 일정곡률기법을 적용한 시추궤도길이 항과 KOP의 분포하중크기 항으로 목적함수를 구성한다. 이를 통해 기존 연구와 달리 작업자 개인의 경험적 지식 없이, 시추궤도길이 최소화는 물론 분포하중의 크기를 줄이고 버클링에 대해 안전한 최적의 시추궤도를 설계할 수 있었다. 하중의 지역적 편중현상과 헬리컬버클링으로의 전이 위험구간을 피함으로써, 수평정 시추나 시추궤도의 분포하중 크기가 큰 시추환경에서도 버클링에 대해 안전한 시추궤도를 설계할 수 있었다.
- 최종근, 2007, 지구통계학, 제1판, 시그마프레스, 서울.
- Aadnøy, B.S., 2008, “Theory and application of a new generalized model for torque and drag,” Proc. of the SPE Asia Pacific Drilling Technology Conference and Exhibition, SPE, Jakarata, Indonesia, August 25-27.
- Aadnøy, B.S. and Andersen, K., 2001, “Design of oil wells using analytical friction models,” J. of Petroleum Science and Engineering, Vol. 32, No. 1, pp. 53-71.
- Guo, B., Miska, S., and Lee, R.L., 1992, “Constant curvature method for planning a 3-D directional well,” Proc. of the SPE Rocky Mountain Regional Meeting, SPE, Casper, Wyoming, May 15-21.
- Helmy, M.W., Khalaf, F., and Darwish, T.A., 1998, “Well design using a computer model,” SPE Drilling & Completion, Vol. 13, No. 1, pp. 42-46.
- McCann, R.C. and Suryanarayana, P.V.R., 2001, “Horizontal well path planning and correction using optimization techniques,” J. of Energy Resources Technology, Vol. 123, No. 3, pp. 187-193.
- Qiu, W., Miska, S., and Volk, L. 1998, “Drill pipe/coiled tubing buckling analysis in a hole of constant curvature,” Proc. of the SPE Rocky Mountain Regional Meeting, Midland, Texas, March 25-27.
- Rudolf, R.L., Suryanarayana, P.V.R., McCann, R.C., and Rupani, R.A., 1998, “An algorithm and a program to plan optimal horizontal well paths,” Proc. of the ASME Energy Sources Technology Conference and Exhibition, Houston, Texas, February 2-4.
- Shorkir, E.M., Emera, M., Waly, A., 2002, “Optimal 3-D directional & horizontal wells planning using genetic algorithm,” Proc. of the 26th Annual SPE International Technical Conference and Exhibition, Abuja, Nigeria, August 5-7.
- Shengzong, J. and Xilu, W., 1999, “A new for designing 3D trajectory in sidetracking horizontal wells under multiconstraints,” Proc. of the 1999 SPE Asia Pacific Improved Oil Recovery Conference, Kuala Lumpur, Malaysia, October 25-26.
- Wiggins, M.L., Choe, J., and Juvkam-Wold, H.C., 1992, “Single equation simplifies horizontal, directional drilling plans,” Oil and Gas Journal, Vol. 90, No. 44, pp. 74-79.
- Wu, J. and Juvkam-Wold, H.C., 1995, “Coiled tubing buckling implication in drilling and completing horizontal wells,” SPE Drilling & Completion, Vol. 10, No. 1, pp. 16-21.
- Publisher :The Korean Society of Mineral and Energy Resources Engineers
- Publisher(Ko) :한국자원공학회
- Journal Title :Journal of the Korean Society for Geosystem Engineering
- Journal Title(Ko) :한국지구시스템공학회지
- Volume : 46
- No :2
- Pages :160-170
Journal of the Korean Society of Mineral and Energy Resources Engineers
