Discussion on optimization design method for sidetracking wells in Bohai Oilfield

Sidetracking of inefficient wells in Bohai Oilfield is one of the important means to stabilize production and increase production. Optimizing the sidetracking scheme to achieve cost reduction and efficiency enhancement is the research focus of refined sidetracking well design. In this paper, the theory of sidetracking technologies is introduced and optimization of sidetracking place is gived based on the location match of the low-efficient well and the sidetracking well and sidetracking plans in deep and shallow strata is identified. To aim at the shallow sidetracking scheme, The applicable conditions and difficulties are proposed in different cases for reentry technology of marine riser, sidetracking under insulator shoes, surface casing windowing sidetracking, sidetracking under surface casing shoes. Aiming at the deep sidetracking scheme, the optimal flow of the casing sidetracking scheme and sidetracking under production casing shoes is proposed. Taking two low-efficiency wells of A and B in Bohai as an example, the preferred slot and the sidetracking section are preferred, and the sidetracking point is preferred. Finally, the sidetracking location of the two wells is interchanged, and the footage is saved at 1428m. The on-site implementation results show that the two low-efficiency well sidetracking schemes are reasonable and can achieve the purpose of cost reduction and efficiency enhancement. The optimal method of low-efficiency well sidetracking proposed in this paper has certain guiding significance for the sidetracking design of low-efficiency wells in Bohai Oilfield.