Operational and safety aspects of drill stem testing—getting it right

Abstract

Drill stem testing (DST) is recognised by many operating oil and gas companies to be one of the most hazardous operations routinely undertaken. Well testing has a higher potential for loss of life, loss of assets, environmental catastrophe and budget overrun than any other time in the exploration operations. Therefore, it is of great importance to the industry that such operations are extremely well planned and executed. Planning a DST is an extremely complex task and requires a great deal of experience. This paper provides an insight into the techniques and procedures that are used in all the major operational and safety aspects of oil and gas DST. It uses a structured approach to guide the reader through the various best practices that are required to effectively plan and implement a DST operation under just about any circumstances worldwide, onshore or offshore. The project also includes design parameters for contingency conditions that were not normally present during equipment operations but could exist in emergency situations. Problems and solutions associated with perforation, adverse hole conditions, and high-pressure, high-temperature (HPHT) conditions are also presented. Additionally, this paper includes an overview on environmental requirements, which provides information associated with risk management and legislation.