Abstract: The present disclosure relates to compositions and methods for the removal of deposits from oilfield apparatus and wellbore surfaces. In particular, removal of deposits comprising heavy hydrocarbon materials and finely divided inorganic solids. The composition includes a mixture of a corrosion inhibitor component which is morpholine or a morpholine derivative having corrosion inhibitor properties, and a surfactant which is a quaternary ammonium compound having biocidal properties. Methods of removing a deposit from a surface or unplugging an oilwell which has been plugged with a deposit, are also included wherein the method comprising contacting the deposit with a composition as disclosed herein for a selected period of time.

Abstract: The present disclosure relates to compositions and methods for the removal of deposits from oilfield apparatus and wellbore surfaces. In particular, removal of deposits comprising heavy hydrocarbon materials and finely divided inorganic solids. The composition includes a mixture of a corrosion inhibitor component which is morpholine or a morpholine derivative having corrosion inhibitor properties, and a surfactant which is a quaternary ammonium compound having biocidal properties. Methods of removing a deposit from a surface or unplugging an oilwell which has been plugged with a deposit, are also included wherein the method comprising contacting the deposit with a composition as disclosed herein for a selected period of time.

Abstract: A method of treating a fluid to reduce the level of H2S therein while inhibiting the deposition of scale on surfaces in contact with the fluid, comprising introducing into the fluid a triazine scavenger compound and a terpolymer. The fluid may be liquid or gas and may be petroleum, petroleum product, natural gas, liquefied petroleum gas or other type of oil fraction or refined oil. The triazine scavenger may be e.g. 1,3,5-tri(2-hydroxyethyl)-hexahydro-1, 3, 5-triazine. The terpolymer may comprise a carboxylate/sulphonate/non-ionic terpolymer. When added to a wellbore fluid, it is effective as a scavenger of H2S and also reduces the amount of scale deposition on a surface in contact with the fluid when the fluid comes into contact with or is mixed with a brine. In some aspects, the composition increases the proportion of precipitated solids held in suspension when the fluid is contacted with or mixed with a brine.