Maximizing production from brown-fields and extending the plateau have become utmost priorities for exploration-and-production companies the world over. This calls for a synergistic approach involving close coordination of various disciplines—subsurface, surface, well drilling and completions, and facilities engineering—to achieve the common goal of maximizing production and recovery. There is a growing awareness that maximizing field production involves not only having a clear understanding of subsurface intricacies but also ensuring that existing surface facilities are performing at their best to handle production in an environmentally safe manner. Many papers presented during the past year at SPE conferences and surveyed for this review address these issues.
Infill drilling and optimization of ongoing waterflood are two activities planned for revitalization of mature fields. Drilling through differentially depleted, multilayered reservoirs and the untapped deeper zones is a challenging task. Robust knowledge of rock properties, formation pressures, magnitude of in-situ stresses, and their evolution with production and depletion is essential for successful drilling of new wells in the redevelopment of mature fields. It is necessary to apply several tools to identify locations of bypassed oil and corroborate the findings of these tools before making a final decision. This becomes even more challenging when there is low resistivity contrast, such as in freshwater environments or in certain cases where openhole logging is not possible because of poor borehole conditions. Operators have calibrated numerical-simulation models successfully with innovative logging tools to locate and produce new oil from old fields.
Rejuvenation of mature assets plays a crucial role in the current low-oil-price scenario, allowing for improved production with limited investments and risks. Nevertheless, brownfield rejuvenation is often very demanding in terms of complex integrated reservoir studies, which typically take several months to complete. The new and emerging technology of applying analytical and data-driven models provides fast solutions to diagnose ongoing waterflooding processes effectively and examine low-cost strategies to improve areal- and vertical-sweep efficiencies.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 184902 Effects of Pressure Depletion on Stress-Field and Casing-Load Alteration in Mature Fields: A Case Study by Peng Zhang, Halliburton, et al.
SPE 185412 Effective Waterflood Management in Complex Carbonate Reservoir of Mumbai High Field by N.T. Ravi, ONGC, et al.
SPE 186004 Developing Infill and EOR Opportunities While Managing Subsurface Uncertainties in a Mature Complex Field Using Probabilistic Dynamic Modeling by R. Abd Karim, Petronas, et al.