Abstract: The present invention relates to friction reducers and to well treatment fluids. In one embodiment there is provided a friction reducing composition comprising (a) a phosphonium compound and (b) a polymeric friction reducer. In a further embodiment there is provided a well treatment fluid comprising a phosphonium compound.

Abstract: A method of removing trapped hydrocarbons from pipework, the pipework comprising a through pipe (1) extending from an inlet to an outlet, and at least one up-pipe (2a, 2b) extending upwardly from the through pipe. The method comprises: flushing the through pipe with a water-based liquid (6) which has a density less than hydrocarbons; wherein the water-based liquid comprises a plurality of rigid containers, such as microspheres, the rigid containers each having a sealed void containing a gas. in this way, hydrocarbons in the up-pipes may be removed without hot-tapping them. The flushing may be performed by directing pipeline pigs (5a, 5b) in front of and behind the water-based liquid. The pigs may be a cross-linked gel, based pipeline pig with elastomeric properties. A kit of parts for such a method is also disclosed.

Abstract: A method treats an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include (a) a phosphonium compound; and (b) a compound having formula: M(XO2)n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.

Abstract: The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to said aqueous system, wherein said treatment agents include: (a) a phosphonium compound; and (b) a stabilised halogen containing composition.

Abstract: A biocidal additive includes a blend of a biguanide compound and a polymeric ammonium compound. A method of treating a water system includes adding a biocidal additive to the water system to achieve a minimum inhibitory concentration or greater in the water system. In exemplary embodiments, the water system is a well treatment fluid for oil and gas applications, the blend is a synergistic blend, the biguanide compound is polyhexamethylene biguanide, and the polymeric ammonium compound is poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride].

Abstract: The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include: (a) a phosphonium compound; and (b) a compound having formula: M(XO2)n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.