Well Placement Optimization in a Gas Condensate Reservoir to Prevent Condensate Banking

Abstract

Horizontal wells with multistage hydraulic fractures have become the most common practice to obtain viable commercial production from shale and tight gas reservoirs. With a marked increase of gas production emerging from these tight reservoirs, it is necessary to further study the effects of formation damage due to condensate dropout and how best to prevent and mitigate this damage. There are two common ways to mitigate and treat condensate banking. The first method is to fracture the existing well. This allows bypassing the condensate and therefore increasing well productivity. The second method is to shut-in the well and allow pressure to build up so that the dropped out liquids are revaporized back into the gas. These options, respectively, involve large capital expenses and temporary decrease of production. Before deploying these solutions, the condensate dropout damage can be strongly reduced at no (field) cost by optimizing the well location.This objective in this study was to determine the optimum well location to mitigate formation damage due to condensate dropout in a tight gas well. Compositional reservoir simulations were conducted with different condensate gas ratios and relative permeability curves to quantify the loss of productivity due to formation damage under different conditions. The target formation was 100 ft thick, and a tartan grid was used to represent the hydraulic fractures within the tight gas well.This study determined that well placement plays a key role in preventing damage due to condensate banking. The optimized placement of the well can drastically enhance the viability of a project by allowing for a larger recovery.

A numerical algorithm for group control of conventional/unconventional production wells in hydrocarbon reservoirs

“…The oil recovery from a reservoir can be managed and also be enhanced by different ways, such as improving of the well placement and also controlling the operating condition of existing wells. In the former, it is generally assumed that the number, location and even type of wells are unknown and an optimizer, in general, is used to determine nearly optimal solution (Bangerth et al, 2006;Zandvliet et al, 2008;Emerick et al, 2009;Li and Jafarpour, 2012;Evans et al, 2016). In the latter, which is named well control problem, the reservoir wells operate under controlled conditions which can generally be determined by optimization approaches and also non-optimization models.…”