Predicting and Preventing Oilfield Scale; The Value of Accurate Chemical Analysis and Correct Sample Handling Procedures

Abstract

Predicting and Preventing Oilfield Scale; the Value of Accurate Chemical Analysis and Correct Sample Handling Procedures

Scale formation within oil wells or in production facilities gives a significant cost to the oil industry in both time and money. With the correct data set it is possible to assess the risk and the type of scale formation, and this information can be used to lead plant design or in the selection of an appropriate chemical inhibitor regime. The cost of obtaining this knowledge is very small in comparison to the millions of dollars spent in construction or the time spent cleaning or replacing scale damaged equipment.

Knowledge of the different types of scale and their various formation triggers dictates what parameters should be tested for, when each test should be performed, and the most appropriate method. The chemistry of a produced water can change significantly between the sample point and the point at which it arrives for analysis, and it si also important to be aware of the potential for chemical interference from common elements in produced water.

The acquisition of representative water analyses is crucial in accurately predicting scale formation. This paper will discuss the key variables, and how incorrect sampling or analytical procedures can generate deceptive results. The various software and laboratory based methods of scale prediction will also be covered.