Hydraulics Approach to Deep Well Blowout Control
Authors: West E.R. 
Published: December 2007

This paper was prepared for the Rocky Mountain Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Casper, Wyoming, May 15–16, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Blowouts are one of the most critical and expensive occurrences in deep gas well drilling. Most operators are interested in developing sound well control methods to minimize the hazard.

Several well control methods have been proposed by the industry. Some are highly proposed by the industry. Some are highly theoretical and much too complicated for field use. Nearly all begin by recommending that a "kicking" well be shut in to measure pressures. Often this procedure is impractical. A typical drilling situation where the well cannot be closed in is reviewed.

A well control method using common hydraulic fluid-flow equations is described. This method allows a well to be controlled and killed without shutting in the well. The operator can calculate his bottom-hole hydrostatic pressure at any time without being shut in. The well's potential can quite accurately be estimated while it is being killed.

A theoretical well killing problem is used to demonstrate the hydraulic approach. Hydraulic friction loss equations are presented. Friction loss equation, P = KQn is plotted as a straight line on a log-log plot with the slope of n = 1.82.

To adequately handle gas cut mud, a well should be equipped with a mud separation unit and a remote controlled hydraulically operated high pressure choke. A description of this equipment is presented.

HNG Oil Co. applied the hydraulic well control method to save a $1 million drilling well in West Texas. Mud separation units and hydraulically operated chokes were used in accomplishing the task.

This paper is presented for the express purpose of describing a simple, practical well purpose of describing a simple, practical well control method that can be field applied to minimize the hazards of well blowouts.

Introduction

With the advent of deep drilling in the early 1960's came potential blowouts and high drilling costs. To combat costs, underbalanced drilling of high pressure formations was employed. Millions of dollars have been saved by this method. It, however, creates even more chance for a blowout. Any underbalanced high pressure, high volume formation is a potential pressure, high volume formation is a potential kick zone.

Deep drilling has required much better supervision and well control than before.