Optimization of Production in Slanted Horizontal Wells in Tight Reservoirs

Abstract

Economic production from tight-oil formations requires the same hydraulic fracturing techniques used during production of shale gas, and the same horizontal well technology is often used. Tight-oil formations are heterogeneous and greatly vary over relatively short distances. Thus, even in a single horizontal drilled hole, the amount recovered can vary, just as recovery within a field or even between adjacent wells can vary. This can make evaluation and decisions regarding profitability difficult. In relatively thinner pay zones, horizontal or slanted wells can be successful in terms of productivity as long as robust reservoir management is applied with well designs that consider both geology and operational control variables. Thus, it is crucial to understand every control and uncertainty parameter to help maximize efficiency and recovery within such systems.Robust commercial optimization and uncertainty software is coupled with a full-physics commercial simulator that models this phenomenon to investigate the significance of major parameters on the performance of horizontal wells in tight-oil formations.Slanted wells provide more flexibility and access to pays than vertical wells drilled from the same surface location, which is of more significance in tight formations because of less communication between zones. The results of the study not only confirm this, but also show the increased value provided using slanted wells compared to vertical wells in tight formations. The study also illustrates the significance of each optimization and uncertainty variable in terms of the success of recovery from slanted horizontal wells in tight formations.The results and sensitivities are compared and discussed considering a comprehensive literature review of recycling gas-condensate reservoirs using different process optimization methods. The significance of all major parameters is outlined using tornado charts to serve as a practical example for optimization of similar future applications. Vertical, Slanted and Horizontal WellsThe technology for drilling horizontal wells to increase reservoir drainage areas has been used for many years. As directional drilling technology has advanced, the cost of drilling directional wells has been reduced, and the accuracy of drilling has been significantly improved.

Statistical analyses of reservoir and fracturing parameters for a multifractured shale oil reservoir in Mississippi

“…The time at the end of the linear flow can be estimated by using the time at the end of half‐slope. Previous studies have shown that pressure propagation reaches the boundary before the end of half‐slope . The time at the end of the linear flow of a multifracture horizontal well is approximately 0.32 times at the end of the half‐slope (ie, t elf = 0.32 t ehs ) according to Tabatabaie et al Therefore, the time at which the liner flow ends is about 12.8 days.…”

“…Previous studies have shown that pressure propagation reaches the boundary before the end of half-slope. 17,22 The time at the end of the linear flow of a multifracture horizontal well is approximately 0.32 times at the end of the half-slope (ie, t elf = 0.32t ehs ) according to Tabatabaie et al 26 Therefore, the time at which the liner flow ends is about 12.8 days. The matrix permeability is computed to be 0.051 md, according to Equation (1).…”

“…Previous studies have investigated the relationship between production rate and underlying factors such as reservoir characteristics, geological parameters, stimulation parameters, and completion parameters. [21][22][23] Esmaili et al 21 presented a data-driven analysis of completion and hydraulic fracturing parameters, including stimulated lateral length, number of clusters, cluster spacing, and minimum distance to the offset well. Temizel et al 22 illustrated the significance of parameters that can affect production rate or cumulative production.…”

“…[21][22][23] Esmaili et al 21 presented a data-driven analysis of completion and hydraulic fracturing parameters, including stimulated lateral length, number of clusters, cluster spacing, and minimum distance to the offset well. Temizel et al 22 illustrated the significance of parameters that can affect production rate or cumulative production. They investigated the major parameters affecting the performance of horizontal wells in tight formations.…”

Effect of Well Orientation on Oil Recovery from Waterflooding in Shallow Green Reservoirs: A Case Study from Central Africa

“…Despite the volume of published literature [26][27][28][29][30][31][32][33][34][35][36][37][38] on the recovery efficiencies of different well types, to the best of our knowledge, there has been no research on the performance of highly deviated wells in the highly heterogeneous shallow reservoirs of the Central African Rift Valley region, which are significantly different from most moderate-depth to deep reservoirs in other parts of world. This is because of (i) the complications associated with drilling along a precise path within an inclined path, (ii) difficulties encountered in preventing sand influx, and (iii) challenges encountered during screen installation for sand production control, which render directional drilling more difficult and time-consuming for complex reservoirs.…”