Prediction and Monitoring of Oilfield Carbonate Scales Using Scale Check©

Abstract

One of the major problems facing oilfield operations is the occurrence of scale. In oilfields the mixture of produced water and formation water is unavoidable as produced water can be used to enhance production through water re-injection. The occurrence of scale in oil wells may cause flow restriction resulting in production damage, emergency shutdowns, increased maintenance costs due to frequent work-overs and an overall decrease in the production efficiency. Formation water from field XYZ in the Niger Delta region was analyzed to predict the scaling tendency of the water using the General Solubility Index for Calcium carbonate. A scaling program Scale-Check© was written based on the Stiff-Davis predictive model, Langelier's predictive model and the General Solubility Index; these helped to calculate the scaling Index. Scale-Check© was used to predict the scale formation tendency of calcium carbonate scale for Well XY over three periods within the life of the well. Sensitivity analysis that showed the effect of temperature and pressure on carbonate scaling was also implemented. Scale-Check© presents an easy-to-use program for checking the scaling tendency of formation or produced water and hence putting in place proactive measures that go a long way to reduce the negative effects of scaling in the oilfield.

Geochemical modelling of petroleum well data from the Perth Basin. Implications for potential scaling during low enthalpy geothermal exploration from a hot sedimentary aquifer

“…By far the most notorious scaling phase in oilfield as well as geothermal production from sedimentary basins is, however, calcite (Arnórsson, 1989;Benoit, 1989;Dalas and Koutsoukos, 1990;Oddo and Tomson, 1989;Pátzay et al, 2003;Stáhl et al, 2000;. Predicting, quantifying and preventing the carbonate scaling problems that may occur in wells and surface equipment during fluid extraction operations is of crucial importance (Eseosa and Atubokiki, 2011;Garcia et al, 2006;Larsen et al, 2008). In order to assess the carbonate scaling risk and anticipate potential remedies or counter measures, key parameters of the clastic reservoir have to be known, such as the mole fraction of dissolved carbon dioxide and the related bubble point.…”

Research on the Scaling Mechanism and Countermeasures of Tight Sandstone Gas Reservoirs Based on Machine Learning

“…Under the complex conditions in the wellbore, these scaling ions form insoluble scale deposits, leading to wellbore blockages and causing significant losses [5]. Conventional methods to address scaling issues mainly involve chemical means to delay or prevent the formation of scale deposits [6][7][8][9][10][11], or using mechanical methods to remove scaling deposits from the pipe walls [12]. The target block once employed a detoxifier primarily composed of organic sulfonic acid.…”