The formation of calcium naphthenate deposits is recognized as a major flow assurance issue in many fields, and will continue to grow in importance as the volume of heavy/high TAN crudes produced increases. The mechanisms and parameters that determine whether these deposits will form under field conditions are still poorly understood, and much effort is being spent on understanding these more fully.
Scaled Solutions has set up an advanced organics studies laboratory with the capability of standard oil assay (C number distribution, SARA, rheology, etc.) and additional performance evaluation of chemicals used for treating problems of wax, asphaltenes and other organic deposits under system conditions. The sections below show some of the highlights of these developments.
A Dynamic Asphaltene Instability Test rig (DAIT) apparatus (designed in-house) has been developed to investigate the stability under flowing conditions of asphaltene containing oils. The DAIT has been used to:-
The apparatus is now available for testing of crude oils and chemical additives for asphaltene stabilisation.
At Scaled Solutions we have designed dynamic naphthenate flow rigs that are now used to investigate the formation and inhibition of calcium naphthenate deposits in the laboratory under conditions closely resembling those found in the field. These test rigs complement the somewhat limited conventional bottle tests, the results of which often do not represent the operator’s reality. Our dynamic flow rigs have been validated in field studies and are routinely used to assist in the determination of field treatment designs. More recently we have expanded our capability in emulsion testing to allow tests to be conducted at 100°C and 100 Barg using purpose-built emulsion rigs.
In addition to standard wax testing, Scaled Solutions have designed and built an in-house apparatus to evaluate both wax crystal formation and deposition. This, together with analysis and rheological studies, enables system relevant organics issues to be evaluated.