Advancements in Paraffin Testing Methodology

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractPredictive methods for wax deposition within pipelines make extensive use of diffusion models to account for the amount of wax being deposited. Laboratory testing methods commonly rely on deposition results from so-called coldfinger devices to assess deposition tendencies. While these experiments are primarily done for testing chemical inhibitor performance, they serve here as the basis for a cross-reference to the oftenused diffusion models. An empirical heat transfer model is developed to adequately address the heat transfer within this device. Oil analysis data in combination with thermodynamic prediction routines are used to prepare the necessary nparaffin solubility charts. While the heat transfer and solubility data are used for a diffusion-type wax deposition, an empirical deposition model is developed to describe the deposition process. It is illustrated how practical information such as deposition tendencies can be gained from these cold finger devices. An assessment of chemical inhibitor performance is made.

An Investigation of Two-Phase Oil/Water Paraffin Deposition

“…From the results obtained, a model developed by Weispfennig (2001) was used to correlate wax deposition between the cold finger and the pipe flow. The TUWAX deposition model was modified to include two-phase oil/water properties necessary to run the simulator.…”

“…The Reynolds number for the cold-finger tests can be calculated with Eq. 1 proposed by Weispfennig (2001):…”

“…A model to correlate wax deposition between the cold-finger device and pipe flow proposed by Weispfennig (2001) is used in this study. Applying the Chilton-Colburn analogy, Weispfennig proposed the following expression relating the pipe flow and the cold-finger mass-transfer processes: Appropriate heat-transfer correlations for cold-finger-type configurations could not be obtained in the literature.…”

Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

“…Since this project initiation, an extensive search for wax deposition method in pipe has been ongoing. Three methods have been identified including flow loop, cold finger and pour casting [6][7][8]. Based on these methods, an alternative deposition method is developed specifically to suit the study.…”

Paraffin Crystal and Deposition Control By Emulsification

“…2,3,4 A test procedure that considers only the oil phase such as the measurement of the WAT or amount of material that deposits on a cold finger or in a flow loop is simpler to design and implement, but it neglects the presence and possible effect of an aqueous phase on the wax deposition process. This mixed water/oil phase case is a common and practical situation where raw produced fluids are transported through pipes in cold environments and have a risk of wax forming on the pipe walls.…”