Calculation method for additional pressure drop in the development of laminated sandstone reservoirs with multiple layers

Multi-layer commingle production is a common development technique to improve the overall oil recovery of multi-layer laminated sandstone reservoirs. However, grasping the additional pressure drop of each production layer flow accurately, a large amount of production testing data needs to be collected, which significantly increases the cost of oilfield development.Therefore, in order to reduce oilfield development costs as much as possible, it is necessary to establish a model to accurately calculate the additional pressure drop generated by fluid flow within multi-layer stacked reservoirs. Firstly, according to the fluid mechanics, establish the relationship between wellbore frictional pressure drop and flow distance; Secondly, derive the expressions for the additional pressure drop and bottomhole flow pressure of a single-layer reservoir based on the principles of flow mechanics; Finally, by associating the expressions for the difference in bottomhole flow pressure and wellbore flow pressure drop of each production layer, a flow additional pressure drop model for each oil layer in multi-layer reservoir development was established. This model has been applied to multi-layer laminated reservoirs, and the error between the calculated value and the actual test value at the mining site is 0.29%~4.9%, the average error is 2.84%, which confirmed this method feasibility.