scope:

General

This standard describes two test methods for evaluating water quality for subsurface injection: Procedure A-rate versus cumulative volume test (for water-quality monitoring) and Procedure B-suspended solids test (for diagnosis or monitoring). These two test methods are intended to provide standardized water quality in the petroleum production industry. The test methods describe the apparatus required, test conditions, test procedures, reporting procedures, and supplementary tests. Interpretation of the results is beyond the scope of this standard. The bibliography supplies sources of interpretation methods.

Before establishing a test program, the aim of the test should be determined and appropriate criteria for evaluation of the test results should be established. For example, if the intent is to use membrane filtration as a simple water control test, the control criterion might be a given slope of the filtration curve. If diagnostic information is required, more emphasis may be placed on qualitative information, such as the shape of the filtration curve, or spot tests on the filtered solids as well as visual examination of the filter immediately after the test.

Membrane filtration may also be used to monitor pickup of suspended solids from the formation, in which case quantitative determination of solids on the filter may be the selected criterion. Each situation should receive an appropriate review of the parameters involved.

The injection behavior of subsurface formations varies widely, and results of water-quality tests apply only to the system being tested. Application of the results obtained by these tests, therefore, is strongly influenced by the requirements of each subsurface injection project. This standard should be used for routine monitoring of water quality, diagnosing of problems, evaluating effects of system changes and upsets, and monitoring effects of chemical treatment. The manner in which the test results are used depends on the requirements of the specific injection system.

This standard is applicable only when precautions are observed to ensure that the sample is representative of the water in the system of interest. It is not the purpose of this standard to imply that the results or their interpretation may be arbitrarily applied to other water injection projects.