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 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: The method includes a step of introducing into the reservoir, via a well, a mixture comprising a scale inhibitor, a first scale precursor and a second scale precursor. The first and second scale precursors can react together to form scale. The first scale precursor may be an ammonium salt. The method can further comprise a step of stopping the introduction into the reservoir of the mixture and shutting in the well for 2-24 hours, and a step of introducing into the reservoir a further mixture comprising a scale inhibitor, a first and second scale precursor which can react together to form scale. The steps of stopping and resuming the introduction of mixtures may be repeated at least once. The components of the mixtures may be provided as concentrated solutions and diluted in a stream of water prior to being introduced into the reservoir. The method provides an effective way of generating a barrier to fluid flow in a reservoir. The method may be a method of abandoning an entire well in a reservoir.

Abstract: A method of a bandoning a well in a reservoir. The method including the step of forming a scale in the reservoir by introducing into the reservoir a first solution comprising a first scale precursor and a second solution comprising a second scale precursor and a scale inhibitor. The first solution and second solution are able to react together to form the scale. The method further includes the step of at least partially filling the well with cement.

Abstract: The method includes a step of introducing into the reservoir, via a well, a mixture comprising a scale inhibitor, a first scale precursor and a second scale precursor. The first and second scale precursors can react together to form scale. The first scale precursor may be an ammonium salt. The method can further comprise a step of stopping the introduction into the reservoir of the mixture and shutting in the well for 2-24 hours, and a step of introducing into the reservoir a further mixture comprising a scale inhibitor, a first and second scale precursor which can react together to form scale. The steps of stopping and resuming the introduction of mixtures may be repeated at least once. The components of the mixtures may be provided as concentrated solutions and diluted in a stream of water prior to being introduced into the reservoir. The method provides an effective way of generating a barrier to fluid flow in a reservoir. The method may be a method of abandoning an entire well in a reservoir.

Abstract: A method of a bandoning a well in a reservoir. The method including the step of forming a scale in the reservoir by introducing into the reservoir a first solution comprising a first scale precursor and a second solution comprising a second scale precursor and a scale inhibitor. The first solution and second solution are able to react together to form the scale. The method further includes the step of at least partially filling the well with cement.

Abstract: A method of insulating pipeline bundles used in recovering hydrocarbons from wells is disclosed. A polymeric substance, such as an orthophosphate ester, is injected into the annulus between a carrier pipe and the hydrocarbon conveying tubulars. A ferric salt, such as ferric sulphate, may be added as a gelling agent. The mixture results in a gel having a dynamic viscosity of greater than (1000) PaS. The gel insulates the inner hydrocarbon-conveying tubulars from the surrounding seawater thus helping to maintain the relatively high temperature therewithin. This in turn reduces the likelihood for chemicals, such as hydrates, to be precipitated out of the oil phase.

Abstract: The present invention concerns a buoyant fluid comprising a liquid and a plurality of rigid containers, the rigid containers each having a sealed void containing a gas. A particular use is to transport heavy objects subsea. The gas in the rigid containers provides buoyancy but does not compress at different subsea pressures. Therefore effective buoyancy control subsea is much easier compared to known methods. For certain embodiments, a secured supply container may be provided subsea to supply the liquid and rigid containers to a lifting device having a container therefor and an attachment mechanism secured to the object being transported. The liquid is preferably a biodegradable substance such as vegetable oil.

Abstract: The present invention concerns a buoyant fluid comprising a liquid and a plurality of rigid containers, the rigid containers each having a sealed void containing a gas. A particular use is to transport heavy objects subsea. The gas in the rigid containers provides buoyancy but does not compress at different subsea pressures. Therefore effective buoyancy control subsea is much easier compared to known methods. For certain embodiments, a secured supply container may be provided subsea to supply the liquid and rigid containers to a lifting device having a container therefor and an attachment mechanism secured to the object being transported. The liquid is preferably a biodegradable substance such as vegetable oil.