Abstract: Pump having a pump inlet, a pump outlet, at least two threaded rotors and a pressure controlled valve. The pressure controlled valve is capable of controlling re-circulation of fluid from the pump outlet to the pump inlet. The pressure controlled valve can be a control valve. A multiple stage pump assembly is also provided having least two pumps arranged in series, in which at least one of the pumps is the aforementioned pump.

Abstract: Method of performing a 3-D seismic survey using a plurality of vibroseis sources, and an array of seismic sensors arranged within a survey area. Each vibroseis source emits a distinctive acoustic signal and each seismic sensor of the array is in a continuous state of readiness to detect reflected acoustic signals. The method includes assigning vibroseis points (VPs) to each vibroseis source, moving each vibroseis source to assigned VPs where the vibroseis source emits an acoustic signal, recording the emission time of the acoustic signal by each vibroseis source at its assigned VPs together with the geographic position of the assigned VPs, continuously listening for reflected acoustic signals using the seismic sensors and recording a time domain record of the reflected acoustic signals received by each seismic sensor. Reflected acoustic signals associated with emission of an acoustic signal by a vibroseis source at an assigned VP are then determined.

Abstract: A free-standing riser system connects a subsea source to a surface structure. The system includes a concentric free-standing riser comprising inner and outer risers defining an annulus there between. A lower end of the riser is fluidly coupled to the subsea source through a lower riser assembly (LRA) and one or more subsea flexible conduits. An upper end of the riser is connected to a buoyancy assembly and the surface structure through an upper riser assembly (URA) and one or more upper flexible conduits, the riser also mechanically connected to a buoyancy assembly that applies upward tension to the riser. The riser may be insulated for flow assurance, either by a flow assurance fluid in the annulus, insulation of the outside of the outer riser, or both. The system may include a hydrate inhibition system and/or a subsea dispersant system. The surface structure may be dynamically positioned.

Abstract: Multiple sensors on a drill string can be utilized to perform equivalent circulation density (ECD) analysis. By utilizing multiple ones of the sensors, the pressure drop in each section of the wellbore can be classified. Additionally, the inclusion of multiple sensors in the drill string allows a wellbore to be sectioned into intervals bounded by any two sensors. Pressure events occurring in a single section of the wellbore bounded by any two sensors can be isolated and analyzed. The isolation can be achieved by subtracting the pressure measured on the shallower sensor from that measured on the deeper sensor.

Abstract: The invention relates to an apparatus for simultaneously injecting fluids into a plurality of samples of porous media, comprising: a plurality of holders for the samples of porous media, each holder comprising a sleeve and first and second platens, the first platen having an inlet for an injection fluid and the second platen having an outlet for a produced fluid, and the samples of porous media being arranged, in use, in each of the holders such that the first platen and second platen of each holder contact a first and second end of the sample of porous medium respectively, the inlet of each first platen being in fluid communication with an injection line for injecting fluid into the sample of porous medium arranged in the holder, the outlet of each second platen being in fluid communication with a dedicated effluent line for removing fluid produced from the sample of porous medium arranged in the holder, on-line and/or off-line analytical means for analyzing the fluids injected into each of the samples of po

Abstract: Borehole conditions can be determined using distributed measurement data. Real time data measurements can be taken from sensors distributed along the length of a drill string to assess various conditions or properties of the borehole. In particular, the distributed data can be used for example, to track the progress of a chemical pill or also track the location of different types of borehole fluids, and also to determine the hole size or volume of the borehole.

Abstract: A method and system for evaluating the sample coverage of ultrasonic or radiography (UT/RT) measurements of pipeline wall thickness for statistical validity. A data library contains distributions of in-line inspection (ILI) measurements for other pipelines, calibrated to correspond to UT/RT measurements as needed. The data library for these ILI-measured pipelines also includes statistics generated from Monte Carlo simulation, by way of which various sample coverage levels sample the ILI measurements, for determining whether a measurement exceeds a given threshold or meets another premise related to determining the extreme wall loss measurement for the pipeline. A pipeline with sampled UT/RT measurements is used to identify one or more ILI-measured pipeline datasets that are most similar, and the statistics from those most similar pipeline datasets determine whether the sample coverage of the UT/RT measurements is sufficient to draw conclusions about the extreme value of wall loss in the sampled pipeline.

Abstract: Gravel pack composition containing gravel and a water-in-oil emulsion including (a) an organic continuous phase comprising 0.1 to 5 vol % of the emulsion of non-ionic or cationic surfactant and 0.25 to 3 vol % of the emulsion of sorbitan ester; (b) a dispersed aqueous phase comprising 0.05 to 3 vol % of the emulsion of a partial ester of a polyol with at least one C6 to C22 fatty acid and at least one of an acid, acid precursor, and a chelating agent; and (c) a density control agent. The fluid can display a delayed break of up to about 72 hours to enable clean-up of mud cake.

Abstract: A computer-implemented method for determining one or more operating modes for a crude oil displacement system is provided. The crude oil displacement system is arranged to inject an aqueous displacement fluid into one or more reservoirs, each reservoir comprising a porous and permeable rock formation, wherein crude oil and formation water are contained within a pore space of the rock formation. The crude oil displacement system is for use in displacing crude oil from the pore space of the rock formation. The computer-implemented method comprises the steps of receiving measurement data associated with one or more chemical characteristics of the displacement fluid and one or more chemical characteristics of the rock formation, the crude oil and the formation water of the one or more reservoirs, and inputting the measurement data and data representing a predetermined volume of oil into a computer-implemented predictive model.

Abstract: A computer-implemented method for determining an amount of hydrocarbon fluid present in a rock of a hydrocarbon-producing reservoir is provided. The rock comprises organic matter and porous and permeable inorganic matter. The method comprises the steps of receiving data relating to chemical and kinetic properties of the organic matter, rock lithology data, rock thickness and reservoir temperature and pressure data, inputting the received data into a computer-implemented model, and operating the model. The model operates to a) simulate hydrocarbon fluid generation in the rock based on the input data and thereby determine an amount of generated hydrocarbon fluid, b) generate predicted data, and c) determine a total amount of hydrocarbon fluid present in the rock based on the predicted data.

Abstract: Method of consolidating sand in a subterranean formation by contacting the sand in a first location in the presence of water with a slurry in a liquid medium of cement of average particle size less than 10 microns to produce a mixture including sand, water and cement, the slurry being injected into the formation to the location. A separation step is carried out in which a liquid hydrocarbon fluid is passed into the location to displace from the location at least some of the cement from the mixture. The volume ratio of liquid hydrocarbon fluid to the volume of the slurry injected to the formation is at least 5:1. The mixture is allowed to set to give permeable consolidated sand.

Abstract: Multistage pump comprising a plurality of components which include a plurality of pre-assembled pump modules, having at least one twin screw pump module. The multistage pump further has an elongate sleeve for housing the components, and a securing device attachable or engagable with a portion of the elongate sleeve. The securing device is operable to fixedly retain the components within the sleeve. Each of the pre-assembled pump modules has at least one thrust bearing.

Abstract: A free-standing riser system connects a subsea source to a surface structure. The system includes a concentric free-standing riser comprising inner and outer risers defining an annulus there between. A lower end of the riser is fluidly coupled to the subsea source through a lower riser assembly (LRA) and one or more subsea flexible conduits. An upper end of the riser is connected to a buoyancy assembly and the surface structure through an upper riser assembly (URA) and one or more upper flexible conduits, the riser also mechanically connected to a buoyancy assembly that applies upward tension to the riser. The riser may be insulated for flow assurance, either by a flow assurance fluid in the annulus, insulation of the outside of the outer riser, or both. The system may include a hydrate inhibition system and/or a subsea dispersant system. The surface structure may be dynamically positioned.

Abstract: A method and a system are provided for determining the relative positions of a wellbore and an object. The wellbore is represented by a first ellipse and the object is represented by a second ellipse. The first ellipse represents the positional uncertainty of the wellbore and the second ellipse represents the positional uncertainty of the object. The method includes receiving input data relating to a measured or estimated position of the wellbore and the object. In addition, the method includes calculating an expansion factor representing an amount by which one, or both, of the first ellipse and the second ellipse can be expanded with respect to one or both of respective first and second sets of elliptical parameters so that the first and second ellipses osculate. Further, the method includes determining, based on the calculated expansion factor, position data indicative of the relative positions of the wellbore and the object.

Abstract: A method and system for estimating reservoir pressure in a hydrocarbon reservoir from downhole pressure measurements of producing wells is disclosed. Pressure measurements are obtained from wells in the production field over time, and communicated to a server that applies the pressure measurements for a well to a model of that well. The server operates the model using the pressure measurements to determine an operating mode of the well, such as producing or shut-in. Upon detection of a change in operating mode indicative of an abrupt change in flow at the well, such as corresponding to a shut-in event, additional downhole pressure measurement data is acquired until a steady-state condition is reached. The pressure measurements are used to determine a reservoir pressure, which is transmitted to a responsible reservoir engineer or other user. Modification of the determined reservoir pressure value by the user can be received, and the stored reservoir pressure and well model are updated accordingly.

Abstract: Method for predicting the effect of microbes injected into an oil-bearing reservoir which is capable of being represented by a first computer-generated grid including a first plurality of grid blocks. Measurement data representing the effect of injecting the microbes into a multiple coreflood apparatus is received. The multiple coreflood apparatus has material samples indicative of a rock formation associated with the oil-bearing reservoir, the samples being capable of being represented by a second computer-generated grid having a second plurality of grid blocks, the samples being representative of different regions of the reservoir and being connected such that microbes injected into the first sample are able to flow to the second sample. Data received is input into a computer-implemented reservoir model which simulates the effect of microbe injected in relation to the second grid. The reservoir model generates data indicating the effect of injecting the microbes into the multiple coreflood apparatus.

Abstract: Methods, apparatuses and computer readable instructions for determining the effectiveness of, and for performing, a low salinity waterflood. An ion diffusion distance value is determined based on the rate of diffusion of ions within the rock of a reservoir and the residency time of floodwater within the reservoir. The thickness of the layers of the reservoir are compared to this ion diffusion value to determine the effectiveness of performing a low salinity waterflood and also to enable the effective control of a waterflood and to assist in the determination of locations of wells.

Abstract: Method and apparatus for mitigating slug formation in a multiphase fluid stream flowing through a conduit. The method includes (a) determining the pressure in the conduit upstream of a slugging zone, (b) determining the pressure in the conduit downstream of the slugging zone, (c) determining the actual pressure difference across the slugging zone by subtracting the downstream pressure from step (b) from the upstream pressure from step (a), (d) determining the error between a target pressure difference and the actual pressure difference, (e) producing a signal having a first component which is proportional to the error and a second component which is proportional to the rate of change of the error over time, and (f) using the signal produced in step (e) to control the position of an adjustable choke valve located downstream of the slugging zone so as to stabilize variations arising in the actual pressure difference over time.

Abstract: A method of determining rate and phase of fluid produced from or injected into a hydrocarbon well includes obtaining first temperature and pressure measurements from sensors at the well. The first temperature and pressure measurements are applied to a plurality of predictive well models to calculate an estimated value of fluid rate and phase composition from each of the predictive well models responsive to the temperature and pressure measurements. A first fluid rate and phase composition result is derived from the estimate value of fluid rate and phase composition from each of the predictive well models.

Abstract: The invention relates to the use of a mono-, di- or tri-glyceride of citric acid, or a derivative thereof, as a clathrate hydrate adhesion reducer in a surface coating composition. The mono-, di- or tri glyceride of citric acid is preferably a mono-glyceride in which the fatty acid is a monocarboxylic acid having a branched or unbranched, saturated or unsaturated, aliphatic chain comprising between 12 and 20 carbon atoms, particularly oleic, linolenic, stearic or erucic acid. The surface coating composition can be used to coat at least part of a surface of an assembly for use in hydrocarbon production, transportation, storage or processing.