Fracture Damage Analysis in Tight Gas Reservoirs

Open Access
Author:
Han, Jiahang
Graduate Program:
Energy and Mineral Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
May 13, 2014
Committee Members:
  • Yilin Wang, Dissertation Advisor
  • Luis F Ayala H, Committee Member
  • Turgay Ertekin, Committee Member
  • Virendra Puri, Committee Member
Keywords:
  • Fracture Damage
  • Tight sand gas reservoir
  • proppant damage
  • type curve
  • screening tool
Abstract:
Tight gas reservoirs are low-permeability (< 0.1 mD) formations that must be stimulated in order to flow at an economic gas rate and recover an economic volume of gas. Hydraulic fracturing is the most effective technique of well stimulation in low-permeability reservoirs. The concept of hydraulic fracturing is to change the reservoir flow pattern by creating long and highly conductive flow paths within the reservoir. With a successful hydraulic fracture treatment, reservoir fluids can flow through the highly conductive proppant pack into the wellbore, rather than flowing through the low permeable reservoir rock. In addition, the flow can bypass the near-well damage zone. However, in some cases, the stimulation effectiveness is limited due to fracture damages. Weak proppant pack may deform or even crush under in-situ stress, resulting in decreased fracture conductivity. Only 30% of propped fracture length could be considered as effective length due to gel residue, even as low as 5%. Thus comprehensive studies of identifying and quantifying fracture damages are necessary. In this research, we will propose both simple applicable analytical methods and complex numerical methods in identifying fracture damages. Furthermore, we will evaluate the damage impact on tight gas reservoirs. Suggestions on proppant, fracture fluid selection, and well operation will be proposed to minimize damage.