Field Development and Well Planning in Tight Carbonate Reservoir Using Fracture Characterization and In-Situ Stress Mapping From Core Reorientation Studies: Kuwait Case Study

Abstract

Fracture characterization is vital for efficient field development of naturally fractured Carbonate reservoirs. Successful development of fracture reservoir in the study area was possible due to early recognition of fracture play right from the exploration phase and through careful execution of relevant data acquisition campaign in the initial stages of field development. Comprehensive and integrated studies have been carried out over the past few years to arrive at an understanding of the conceptual model in deciphering structural evolution of North Kuwait Jurassic.Extensive core and image log data was acquired in the initial stages of field appraisal, which helped in comprehensive forward planning in design of deviated and horizontal wells. The data analysis steps included accurate and reliable reorientation of the cores. These data were calibrated with the image logs, along with available seismic attributes, which resulted in better understanding of structural evolution and sweet spotting of horizontal wells. This reorientation of the core data also helped in establishing a number of quantitative fractures attributes such as frequency, spacing, dip-azimuth and aperture along with mapping of in-situ stress directions. The detailed integration of these data also helped in accurately mapping the local and regional present day stress and its variations spatially across the fields. Stress direction across the field was helpful for deciding the azimuth of wells during well planning along with selection of completion strategy for current set of horizontal drilling Campaign.Drilling and testing results have been encouraging through enhanced reservoir performance in these tight carbonate reservoirs, based on these integrated studies.

Application of improved data-driven diagnostics workflow based on coupled hydro-mechanical model for stimulation candidate selection in a complex carbonate reservoir

“…Carbonate reservoirs contain more than 50% of world's conventional hydrocarbon reserves and on average have relatively low recovery factors of 20-30%, due to their inherent heterogeneity, complex pore system (matrix, fracture and vug), and wettability characteristics [1]. Due to a declining trend in the exploration of new super-giant fields and production decline of existing carbonate fields categorized as easy oil, better understanding of the productibility issues surrounding complex and tight carbonates such as permeability and fracture netwrok evolution has become increasingly important [2,3]. Also in recent years, exploration and development companies have gained more interest in development of deep carbonates with more complexities in reservoir rock and fluid behavior and application of improved oil recovery (IOR) techniques such as stimulation to tackle productivity issues [4].…”