Some Practical Fundamentals Of Oil Field Water Handling
Authors: Thornton W.M. 
Published: December 2007

The mountains of literature which have been published in recent years on the problems attendant to oil field water handling testify to the complexity of the subject. There are few aspects of water handling that have not been dealt with voluminously by several authors. The literature includes discussion of all conceivable causes of corrosion, plugging and scale formation, prescribes several remedial measures for each specific problem, and presents numerous case histories in which these problems have been encountered and dealt with varying degrees of success. There also have been discussions of more general nature, telling how to design water systems to avoid problems. The proposed approaches vary from prescribing the simplest closed system for all circumstances to the most complex system including aeration..locculation, sedimentation, chlorinzation, filtration and dearation regardless of circumstances. Equal extremes are encountered with regard to the need for corrosion protection with some authors suggesting use of resistant materials wherever possible and others saying use bare pipe and chemically inhibit if necessary.

To the engineer responsible for satisfactory operation of a water injection system, the literature may inspire more panic than confidence. Must he conduct an exhaustive literature search in an effort to anticipate each possible problem so that they may be avoided" His alternative would appear to be joining the "simple closed system" school and installing minimum plant necessary to gather and pressure the water to its destination. If this route is chosen corrosion resistant pipe and equipment initially or elect to use unprotected pipe and rely on chemical treatments if corrosion problems should develop.

There is, of course, a middle ground which will provide a bit more job security to the young engineer. One frequently traveled route involves inquiring of roustabouts, pumpers and all available service peoples into the troubles and successes of other operators in the area. The system then is designed on the basis of the data obtained and sometimes performs quite well. An even better road, however, is the one on which steps are taken to define the basic chemical and physical properties of the water, or waters, involved, and the plant is designed accordingly with due attention to such factors as the need for corrosion protection in view of the anticipated life of the project.

It is important to recognize at this point that only the most basic properties of a water can be defined by practical means prior to design and construction of a water plant. It is not practical, or even possible, in many cases, to foresee all problems which may arise and prescribe treatments for these problems in advance.

Assuming existing water sources such as a brine being separated from produced oil, a steam or lake, or a previously-completed water well, analyses of carefully collected water samples can provide certain useful information. Such data almost always are adequate to determine if an incompatibility problem exists between two or more available water sources. Similarly, water analysis data can be used to determine in advance if water to be produced at a flood project can be mixed with source water for reinjection or must be handled separately. It usually is possible with these data to determine if a closed system can be considered or if a more complicated open system must be employed. The latter often is mandatory if large volumes of surface water from streams or