Numerical Study on Fracture Sealing Capability of Lost Circulation Materials
Open Access
- Author:
- Lee, Lu
- Graduate Program:
- Energy and Mineral Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- October 01, 2021
- Committee Members:
- Corina Drapaca, Outside Unit & Field Member
Gregory King, Major Field Member
Derek Elsworth, Major Field Member
Arash Dahi Taleghani, Chair & Dissertation Advisor
Mort D Webster, Program Head/Chair - Keywords:
- Lost Circulation
Drilling
Particulate Flow
Numerical Simulation
Fracture Sealing - Abstract:
- Lost circulation is a problem that can jeopardize the drilling and completion operations, which results in a period of downtime. If fluid loss persists, the downtime translates into extra cost spent in order to resume the operation. A lost-circulation event can also lead to other problems such as a kick, stuck pipe, and in a more severe situation, a blowout. There are many reasons why fluid can be lost into the formation. For example, a loss occurs when the fluid column is heavier than the surrounding formation fluid. If the formation rock is highly fractured and/or cavernous, drilling fluid can be lost. The outcome of a loss event is certainly negative where an immediate treatment is required, or a preventive method is needed. Some advanced drilling techniques such as drilling while casing and manage pressure drilling can prevent and minimize the damage due to a loss event. However, they are more costly compared to the use of bridging materials. The cost-effective bridging materials can be of naturally found organic items such as walnut husks, tree barks, and other fibrous materials. The purpose of the bridging materials is to plug and seal the porous space, so that further fluid loss can be stopped. There have been many laboratory studies on various types of materials that can be used as the bridging materials. However, there is not a single effective numerical tool to simulate how these materials flow in a porous channel. With the advance in computational power, it is possible to simulate the particulate flow inside a fracture. A fracture may be plugged when there is a sufficient amount of particles. In addition, the fluid and particle properties would also affect the overall bridging and sealing mechanisms. In this study, a reliable numerical simulation tool is developed and is adopted to simulate fracture sealing. The simulation model can be used to supplement the laboratory work to save costly labor work.