--> Geomechanics of Unconventional Carbonate Oil Reservoir, North Kuwait

AAPG ACE 2018

Datapages, Inc.Print this page

Geomechanics of Unconventional Carbonate Oil Reservoir, North Kuwait

Abstract

The developments of oil bearing unconventional reservoirs are becoming the future of oil industry. Rock mechanical properties play a major role in developing these reservoirs. Assessing reservoir mechanical properties variation, quality and reservoir geomechanical behavior is critical to evaluate its fracture-ability and design the fracturing recipe.

The knowledge of formation mechanical properties is critical to plan place and assess reservoir variations across the horizontal wells trajectory. Acquiring slowness data within the horizontal section is critical to assess formation fracture-ability. Particularly when formation brittleness do not remain constant across the formation. Properties such as, brittleness vs. ductility, Young’s Modulus, Poisson’s Ratio, fracture toughness, radial and circumferential velocity. Shear and Stress Anisotropy analysis. Are computed. These properties were calibrated to core measured mechanical properties.

Carbonate reservoirs are heterogeneous by nature. Considering the low permeability in these heterogeneous carbonate reservoirs makes the need to identify their fracturing ability an important aspect to ensure the correct treatment design, improve production and ensure its sustainability. Resulting fracture conductivity is the key parameter that controls final well productivity and hydrocarbon recovery.

Geomechanical properties are found to vary across the studied reservoir both between wells and across the lateral section trajectory. The knowledge of the reservoir mechanical properties improved the fracturing operation, and provided guidance on multi stage packer placements. Properties such as Young modulus and Poisson ration are found to be requisite to develop a fracture Model, and to identify the variation in reservoir mechanical properties. This played major part in optimizing the frac job, its stages, and the design of its parameters, which eventually created sufficiently conductive propped fracture length that fits the well and its spacing.

Spatial and vertical distribution of geomechanical properties of unconventional carbonate oil reservoir are discussed assessed and mapped across the studied field, these were found to vary. An innovative reservoir geomechanical best practice is developed to locate the intervals that are prone to fracture across the lateral section. Workflow of the best practice in designing multistage fracture spacing in unconventional carbonate oil reservoirs is developed.