In-Situ Mining - A New Opportunity For The Petroleum Engineer
Authors: Huff R.V. 
Published: December 2007

This paper presents the concepts of in-situ mining. Briefly discussed are the growing requirements of the mining industry for borehole technology and the need for engineers who can design and execute drilling and completion of wells. Their need includes engineers who understand fluid dynamics in wellbores, artificial lift systems, and multiphase flow in porous media.

Eventually the industry will demand that in-situ mining engineers who become engaged in copper or uranium leaching activities have a broader training than those petroleum or mining engineers now graduating from our colleges and universities. This new discipline will include not only the classical courses offered in the petroleum engineering curriculum, but also courses such as corrosion resistance of metals and other materials of construction for high-pressure injection and production systems. These engineers will be expected production systems. These engineers will be expected to have a familiarity with the geology end mineralogy of ore deposits suitable for in-situ mining. They will need to be exposed to hydrometallurgical processes, reaction kinetics, and chemistry of various processes, reaction kinetics, and chemistry of various minerals when these minerals are subjected to different leaching reagents.

These new challenges for the petroleum engineer will be exciting but will demand a much broader background in the applied sciences.

Introduction

Petroleum engineering is a profession that applies scientific knowledge to the recovery of oil and gas by the most economic means. There are at least four distinct specialties within the profession: drilling, production, reservoir, and facilities. Except for electives, all petroleum engineers receive essentially the same training in their 4 or 5 years of undergraduate work. Specialization usually follows acquisition of the BS degree. The trained petroleum engineer is skilled in borehole technology petroleum engineer is skilled in borehole technology and flow of fluids through porous media. Because of his understanding of these concepts, he now finds himself in demand by not only the petroleum industry, but also the mining industry.

The mining industry has been developing improved metal and mineral recovery technology. Until recently these improvements have been related to conventional mining methods and processes. During the past two decades the mining industry has gained new perceptions of mineral occurrences and deposit genesis. As a result, new and unique processes for metal and mineral extraction are becoming available. Some of these processes employ borehole technology and many firms now view the use of borehole technology as a viable alternative to conventional mining for some ore bodies.

Borehole technology was used as early as 2,000 years ago by the Chinese for production of water. In addition to production of oil and gas, use of this technology has been extended to the recovery of salt and sulfur. Most of you are aware of the oil industry's interest in in-situ methods for recovering oil from oil shale and the growing interest in geothermal energy because these activities routinely eve reported in the petroleum literature. However, radical changes are taking place in the uranium mining industry and other firms are experimenting with borehole methods for recovery of other metals.

In-situ mining for uranium was begun in the early 1960's in south Texas by Sabine Production Co. At about the same time, Utah Construction and Mining Co. started similar operations in Shirley Basin, WY. Since then a number of mining and petroleum companies have initiated pilot tests and some have expanded into commercial operations.

In-situ mining for copper is not nearly so advanced, but at least two pilot operations have been conducted.

IN-SITU MINING

In-situ mining and in-situ leaching are synonymous processes employed to extract mineral values from the earth without removal of the ore body.