Abstract: An apparatus for determining properties of fluid flowing into a well includes an inflow channel providing a path for fluid to a pipe, a heater arranged to heat at least part of the fluid in the inflow channel, and a temperature sensor arranged to measure the temperature of the fluid in the inflow channel.

Abstract: A method for use in surveying a subsurface region beneath a body of water by detecting compressional, P, waves propagating through the body of water includes locating one or more sensor systems in the water at or close to the subsurface region, using the or each sensor system to detect P waves in the water, and translating all or a portion of the data representing the detected P waves to a higher level above the subsurface region. In the method, the effects of S waves, propagating in the subsurface and converted at the water/subsurface interface into P waves propagating in the water or along the seabed interface, in the translated data is reduced.

Abstract: A method of solving a geophysical inverse problem for estimating a physical parameter, the method comprising providing a model vector representing the physical parameter, transforming the model vector by a first operator to provide a first transformed model vector, solve the inverse problem for the first transformed model vector to provide a first solution, transforming the model vector by a second operator to produce a second transformed model vector, solve the inverse problem for the second transformed model vector to provide a second solution, calculating a weighted sum of the first solution and the second solution.

Abstract: There is described embodiments relating to a method of determining a wave field in an anisotropic subsurface of the Earth. The method includes numerically solving a decoupled quasi-acoustic single wave mode wave equation based on spatially varied anisotropic parameters, to determine the wave field in the anisotropic subsurface.

Abstract: A method of measuring the viscosity of cement slurry used for a primary cementing of an oil or gas well includes pumping the cement slurry along a conduit to a cementing location, measuring a first pressure loss along a first, horizontal portion of the conduit and a second pressure loss along a second, vertical portion of the conduit, and calculating a viscosity of the cement slurry based at least in part on the first and second pressure losses and a flow rate of the cement slurry.

Abstract: A system for optimising injection of a diluent to one, some or all of one or more wells comprising a downhole pump and holding means for the diluent, said holding means being connected to the or each well via one or more injection lines through which the diluent may be pumped by diluent injection means, characterised in that said system comprises measurement means for real time measurement of one or more production performance parameters, and measurement of the rate of injection of the diluent; and means for optimising the injection of the diluent to at least one of said one or more wells on the basis of: (i) means for making controlled variations of the diluent injection into the at least or each well; (ii) means for the processing of the real time measurements of the production performance parameters affected by these variations to determine any necessary adjustment of the injection of the diluent towards an optimal value; and (iii) if required, making the corresponding physical adjustment of the injection

Abstract: There is provided a method of chemically removing iron-containing casing from a well bore comprising injecting an acidic solution into said well bore, wherein said solution contacts said iron-containing casing and thereby accelerates oxidation of iron to iron cations, allowing said iron cations to dissolve in said solution, and removing said solution from said well bore. There is further provided a batch method of removing iron-containing casing from a well bore comprising injecting an acidic solution into said well bore, wherein said acidic solution contacts said iron-containing casing and thereby accelerates oxidation of iron to iron cations, and allowing said iron cations to dissolve in said acidic solution, wherein said well bore is at least partially open to the atmosphere.

Abstract: A method of identifying the phase composition and/or changes in the phase composition of a fluid flowing through a turbomachine includes monitoring changes in at least one electrical parameter associated with operation of the turbomachine, and employing a known correlation between phase composition and or phase composition changes, and changes in the electrical parameter(s) to associate the monitored changes with changes in the actual phase composition of the fluid.

Abstract: The present invention provides a method for inverting oil continuous flow to water continuous flow and reaching one or more desired production parameters in a well producing fluid containing oil and water or inverting oil continuous flow to water continuous flow and reaching one or more desired transport parameters in a pipeline transporting fluid containing oil and water wherein there is a pump in the well or transport pipeline, comprising the following steps: (a) reducing the pump frequency until either inversion from oil continuous production to water continuous flow is achieved or a predefined stopping condition is reached; (b) if inversion has not been achieved in step (a), adjusting the wellhead pressure in the well or the pressure at the reception side of the transport line to achieve the inversion; (c) stabilising the flow at the condition reached in steps (a) or (b); and (d) carefully adjusting one or both of the wellhead pressure and pump frequency to reach the one or more desired production paramet

Abstract: A method of plugging a well in a plug and abandonment procedure includes providing a tubing in a wellbore, in a location for a well plug, the tubing is provided with an internal cable section placed inside of the tubing, and forming a plug in the well in said location for the well plug across the width of the tubing and a surrounding wellbore annulus to create a permanent barrier without pulling the tubing from the wellbore. The step of forming the plug includes substantially removing the internal cable section inside the tubing and forming a fluid-tight seal in the tubing where the internal cable section has been removed, for separating, on either side of the seal, first and second fluid volumes of the tubing.

Abstract: A method of estimating a set of physical parameters, the method comprising iteratively inverting an equation to minimise an error between simulated data and measured data and to provide an estimated set of physical parameters, wherein said iteratively inverting comprises at least a first inversion step and a second inversion step and wherein the simulated data depend on a model vector representing the set of physical parameters, applying a compression operator to the model vector representing the set of physical parameters to reduce the number of free variables and to produce a compressed model vector and varying the compression operator between the first inversion step and the second inversion step.

Abstract: There is described embodiments relating to a method of determining a wave field in an anisotropic subsurface of the Earth. The method includes numerically solving a decoupled quasi-acoustic single wave mode wave equation based on spatially varied anisotropic parameters, to determine the wave field in the anisotropic subsurface.

Abstract: A subsea wellhead assembly 1 comprises: a subsea wellhead 2; a template 6 associated with the wellhead; subsea riser system equipment 4 connected to the wellhead and one or more connection members. The subsea riser system equipment 4 is also connected to the template 6 by the one or more connection members so that lateral support is provided to the subsea riser system equipment 4 from the template. A method of installing the subsea wellhead assembly 1 is also provided.

Abstract: There is described embodiments relating to a method of determining a wave field in an anisotropic subsurface of the Earth. The method includes numerically solving a decoupled quasi-acoustic single wave mode wave equation based on spatially varied anisotropic parameters, to determine the wave field in the anisotropic subsurface.

Abstract: A method for achieving zonal control in a wellbore when using casing or liner drilling includes providing a slotted tubular section in a wellbore while drilling; providing a sleeve adjacent to and radially overlapping with the slotted tubular section, while drilling; and moving the sleeve relative to the slotted tubular section so as to permit and/or restrict flow through the slotted tubular section in one or more selected zones.

Abstract: A method of identifying a material and/or condition of a material in a borehole is described, together with related apparatus. The material may either be between first and second tubulars or between a first tubular and a wall of the borehole. The method may include providing a reference quality factor (Qreference) for one or more known materials in one or more known conditions and measuring a downhole quality factor (Qmeasured) of the material and/or material condition to be identified. A spectral ratio ?=(Qmeasured/Qreference) may then be computed for one or more known materials under one or more known conditions followed by an analysis of the spectral ratios to identify the material and/or condition of the material in the borehole.

Abstract: A method of processing controlled source electromagnetic (CSEM) data is provided for reducing the airwave contribution. CSEM data are acquired, for example using a conventional towed source (4) and receiver (5) arrangement. The recorded data are weighted in accordance with the geometrical spreading of the airwave component. The differences between pairs of weighted data records are then formed.

Abstract: A method of estimating electromagnetic parameters of a geological structure, comprising: providing controlled source electromagnetic, CSEM, data of the structure, calculating a numerical model representing electromagnetic parameters of the structure and generating simulated CSEM data, discretising the numerical model based on prior knowledge of the structure, defining a functional for minimising the distance between said simulated CSEM data and said CSEM data, wherein the functional comprises a regularisation term which depends on prior knowledge of said structure.

Abstract: A method of dynamically generating an acoustic noise map of an industrial zone to be used for protecting operators within the zone from exposure to acoustic noise above a safety threshold, the method comprising collecting acoustic noise data using a network of wireless acoustic sensors located within said zone, generating an acoustic noise map using the collected noise data and a numerical model of the propagation of acoustic noise within the zone.

Abstract: A method and apparatus for direct tie-in of pipelines are disclosed. An apparatus is attached to a portion of a pipeline, the apparatus including a tensioning member and a buoyancy element attached to the tensioning member such that, when submerged, the pipeline is deflected as a result of a buoyancy force tensioning the tensioning member, and on releasing the buoyancy element, direct tie-in of the pipeline is performed.