Feasibility of Using Plasma Assisted Drilling in Geothermal Wells

Abstract

Summary Main reason that prevent companies from investing in geothermal resources is the cost of deep drilling. Also, making fractures in candidate medium to increase permeability to make the heat production operation more profitable. Reducing cost of drilling can reduce the cost of this operation. To achieve this goal, plasma arc can bring heat flux induced and cause some advantages such as rock weakening and increasing the rate of penetration during the operation. This paper investigates the effects of plasma on the rock properties on optical parameters such as expansion coefficient during plasma arc assists drilling and fracturing operations. In this work, an interaction of plasma and rock texture has been investigated experimentally. Limestone sample interacts with a temperature that generated from plasma torch or arc with initiating and propagation fractures. Although, as running experiments for big scales are way too expensive and in some cases impossible with current technology, a numerical model is a suitable option that can be utilized to test different cases before experiment and operations. In this paper, using finite difference and finite element methods, two thermal models have been created for each type of plasma interaction with rock which can suggest some possible results.