Empirical Study of Thermochemical for Heavy Oil Problems in Production Wells

Well "X" is an oil well located in South Sumatra, Indonesia, which started production (on stream) in June 2017 and is still producing today. The fluid contained has the characteristics of heavy oil with a value of 24.6oAPI and a high pour point (HPPO) of 48oC originating from the Talang Akar Formation reservoir. This well was closed after two months of production, the calculation result of the Colloidal Instability Index (CII) of 1.022 indicates that this value indicates instability of asphaltene in crude oil and can cause asphaltene deposits to form. One of the methodologies in overcoming this asphaltene problem is using thermochemical stimulation. This well has undergone two chemical injections using thermo-A1 (xylene, C8H10 12.5%) + thermo-B1 (toluene, C7H8 2.5%). increased, namely thermo-A1 (xylene, C8H10 15%) + thermo-B1 (toluene, C7H8 5%) resulted that the well only lasted 9 days with a rate of 75 BOPD which decreased oil production by 16% per day until shut-in on 18 January 2018 indication of deposition of large quantities of oil in the production tubing. Based on data from the EMR (Electric Memory Recorder) at a depth of 400 m from the surface, the resulting oil temperature is below the pour point, which is 48oC. On July 22, 2018, thermal stimulation with thermochemical was carried out to overcome the problem of asphaltenes. This thermochemical stimulation can melt the asphaltene deposits that settle in the production tubing and can raise the temperature above the pouring point of the oil. The thermochemical stimulation has succeeded in making the well produce again with a Qoi of 325 BOPD and raising the wellhead temperature from 30oC/86oF to 50oC/122oF. The results of the economic analysis of this thermochemical stimulation activity indicated that this activity benefited USD 947,811.