This article describes experience and results of TAML-3 penta-lateral (5-lateral) Fishbone type well construction at East-Messoyakha field. Trial work has been conducted to determine technical and economical feasibility of fishbone well construction.
East - Messoyakha field has very complex geological structure. According to field sedimentary conditions there are 3 major deposition cycles in primary PK 1-3 formation - «А», «B» и «С». Cyclite «B» has a high degree of discontinuity that leads to low production efficiency of horizontal wells.
Hydrodynamic modelling has shown multilateral well technology to be perspective in terms of increase of vertical association coefficient. Utilization of multilateral well technology is very perspective in geological conditions of East-Messoyakha field, it will also increase efficiency of reserves development compared to conventional horizontal wells.
During completion concept selection and planning stage, different options have considered. TAML-3 level have been selected for a multilateral junction. Lateral trajectories well paths were planned to cross sub-layers and turn in azimuthal direction.
Multilateral ERD well construction required multiple technical solutions to be implemented in order to successfully complete the project: running 7" casing in 800 horizontal section, utilization of OBM and its re-use, running lateral liners in two trips.
Successful project execution of penta-lateral allows to solve the following challenges:
extend reservoir coverage and increase of effective well radius in heterogeneous layers
simultaneous drainage in different layers
decrease the risk of production loss due to lateral hole collapse
Cased fishbone multilateral well proved its effectiveness after 6-months production. It is also a logical continuation of company’s technological development. The paper also discusses possible options for further advancement.