Drilling geothermal well

By Ludek | Ludo | 22 Apr 2021


Drilling and well construction (probably one of the most expensive features of a geothermal direct use project) is often the least understood. This chapter provides the basics of equipment and methods used for drilling and completion of geothermal wells. It provides data needed by architects, engineers, and consultants to assist them in specification writing, selection of contractors, and drilling and completion inspection.

Most direct use geothermal wells can be drilled using conventional water well technology and equipment. Most of the wells will produce water at temperatures less than boiling and without artesian flow at the surface; however, some will be hotter or will flow. Blowout preventers and other sophisticated safety equipment are not usually required; however, this does not mean that there are not significant safety considerations that should be addressed. Many of the wells have water above 140oF and this will scald. Public and drilling crew safety must be ensured.

The cementing portion may appear to be overly detailed and long. However, the author's view is that, all too often, cementing is considered simply as a means of plugging up the annulus between the casing and borehole wall. Little attention is paid to methods and materials, and a poor cement job is the
result. This can result in lost production zones, cold water leaking into production zones, geothermal water leaking into freshwater zones, and reduced useful well life. Also, in view of the increasing awareness and concern about inter-zonal migration and possible fresh water aquifer contamination, proper cementing is of increasing importance. A glossary of drilling terms is included at the end of this chapter. For some readers, it may be wise to read this section first in order to fully understand the text.

How do you rate this article?


0

0


Ludo
Ludo

Welcome to my World! Let's look at engineering and mechanics in whole world. A lot od knowledge about geology, drilling and petroleum engineering Open your mind!

Send a $0.01 microtip in crypto to the author, and earn yourself as you read!

20% to author / 80% to me.
We pay the tips from our rewards pool.