Thermochemical Solution for Removal of Organic Solids Deposit In and AroundWellbore and Production Tubing

摘要

During production of crude oil, temperature and pressure ofthe produced fluid decreases along its production pathway.The reduction in pressure and temperature disturbs theequilibrium of the composition of the oil particularly theheavier components leading to their separation, precipitationand deposition at in-and-around well bore (skin effect) andproduction tubing. Such a deposition can choke the flowpassage from reservoir to well bore and reduce the productionof oil appreciably (Diagram 1).A unique two pack chemical system had been developed as aneffective tool for:·Removal of organic deposits, such as in-and around wellbore (skin) and production tubing·Enhancement of production rateThe two pack chemical system when injected into the wellbore through production tubing, reacts to produce in-situ heatwith a reaction product. The heat generated in the system candislodge and melt the deposits and the reaction product formedacts as dispersant and an effective surfactant.The paper presents the results on two wells which were pilotimplemented in Malaysian Offshore field, Temana (TE).Among the two treated wells, one well was a closed-in wellwhile the other was gas lift producing well. Both wells hadshown appreciable decrease in skin factor, reduction in waterproduction and sustained an additional average incrementalproduction of 190 to 320 bpd for the past one year. Pay backperiod of the treatment cost was between 11 to 19 days. Thewells are still producing after one year of treatment.The two pack chemicals system and related chemicals, andtheir reaction product are compatible with crude oil, rockformation, tubular steels and oil field rubber parts.