The Effect of CO2 on Wax Appearance Temperature of Crude Oils

Wax deposition makes up one of the main problems in the petroleum industry. Different types of techniques and treatments have been used to inhibit wax deposition. In this work, crude oils from Malaysian oil fields and Sudanese oil field are studied to determine their wax formation tendency for flow assurance purposes. In addition, effect of CO2 injection on the wax appearance temperature (WAT) for these crude oils is studied. In this paper, the high pressure micro differential scanning calorimetry (HPμDSC) has been employed in order to assess the WAT of the crude oils. Results showed that all these crude oils have a WAT ranging from 26.46 to 53.67°C. This suggests a likelihood of wax production in the reservoir and transportation pipelines. Experimental results showed that the injection of CO2 reduced the WAT of the crude oils to about 8.53°C below its original value.