MATHEMATICAL MODELING OF GEOMECHANICAL BEHAVIOR TARMAT DURING THE DEPLETION OF GIANT OIL RESERVOIR-AQUIFER SYSTEMS

Open Access
Author:
Cirdi, Ayse Pamir
Graduate Program:
Petroleum and Mineral Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Turgay Ertekin, Thesis Advisor
  • Luis Ayala, Thesis Advisor
Keywords:
  • aquifer
  • reservoir
  • tarmat
Abstract:
Tarmat deformation and failure behavior during depletion of a giant reservoir-aquifer system is studied and a mathematical model is developed for this kind of composite systems. Deformation response of tarmat to increasing pressure differential caused by continuous depletion of reservoir is studied. In this context, geomechanical failure that takes place at the instant that the pressure differential reaches a critical value is evaluated. Fracture that occurs after this geomechanical failure is characterized. Fracture permeability that is established due to the characterized fracture is studied. Plate theory, maximum shear stress failure criterion, conventional well test model, Perkins-Kern-Nordgren model (PKN model), Khristianovic-Geertsma-de Klerk model (KGD model), flow through fractures models have been combined in a way such that tarmat behavior in giant reservoir-aquifer systems would be modeled appropriately. This sensitivity analysis, being conducted with parameters of reservoir, rock and fluid properties, proposes a protocol to find relationships and suggests designs in composite systems. The proposed methodology, ultimately, predicts fracture width and fracture permeability that would be developed in a system with a tarmat layer having a certain thickness and a reservoir being produced at a certain production rate and total depletion time.