Development and mechanism of high carbon number paraffin wax blocking remover

Abstract

There are serious wax deposition problems in Yueman block of Tarim Oilfield. It was found that the sediments in Yueman block were mainly composed of high-carbon paraffin, and the carbon number of paraffin was mainly concentrated in C25–C70, of which n-alkanes accounted for 77.14%. A set of evaluation methods (wire mesh filtration method) were created for the deblocking evaluation of high-carbon paraffin deposits. An effective blocking remover formula E4 (150# petroleum ether: 40# dearomatic hydrocarbon solvent (D40): 180# solvent oil (S180) = 3: 1: 1) for high carbon paraffin deposits was developed. Under the condition of a wax ratio of 1: 15 and reaction at 30 °C for 4h, the plugging removal rate (dissolution and dispersion rate of deposit in solvent) can reach 86 %. And it has good universality for other high carbon paraffin sediments, and the deblocking rate can reach more than 80 %. Through the particle size distribution test, it was found that the effect of reaction conditions on the particle size distribution of the deposit was as follows: solvent dosage, reaction temperature, and reaction time. With the enhancement of these conditions, the particle size distribution of organic deposits gradually decreases and the degree of aggregation decreases. From the microscopic analysis, it can be seen that the blocking remover E4 effectively dissolves and strongly disperses the deposit, prevents the aggregation and bonding of the deposit particles, makes the dissolved deposit unable to continue to participate in the agglomeration, and stables dispersion in the solvent.