Optimization design method for sidetracking wells in Bohai Oilfield

Abstract:

Sidetracking from low performance wells in Bohai Oilfield is one of the important means to stabilize and increase production. Optimizing the sidetracking plan to achieve cost reduction and efficiency enhancement is the research focus of the refined sidetracking well design. This paper systematically introduces the sidetracking well design method. The sidetracking section is optimized through properly matching of the low-performance well location and the sidetracking well location; for the shallow sidetracking plan, several technical solutions are presented, including riser reentry, open hole sidetracking from under the riser shoe, sidetracking from surface casing by window-milling, as well as the applicable conditions and difficulties in open hole sidetracking from under the surface casing shoe; for the deep sidetracking plan, the optimal flow chart for sidetracking from the milled window on production casing and sidetracking from under production casing shoes is proposed. Taking two low-performance wells A and B in Bohai as an example, optimization of the drilling slots, the sidetracking well sections was performed. With interchange of the sidetracking target locations of the two wells, the drilling amount was reduced by 1428m. The field application results show that the sidetracking plan for the two low-performance wells are rational and can achieve the purpose of cost reduction and efficiency enhancement. The optimal method of low-performance well sidetracking proposed in this paper can provide some guidance for the sidetracking design for low-performance wells in Bohai Oilfield.