Abstract: Additive for a drilling fluid to block drilling-induced or pre-existing rock fractures comprising polymeric granules with a diameter distribution peak between 1000 and 200 microns and an average resiliency of at least 10% rebound after compression by a load of 200 N and uses thereof.

Abstract: A system and method for releasing a marker within a wellbore is provided. The system and method includes a sensor that detects movement or a position of the marker within the wellbore. The marker may be released in drilling fluid, for example, and may travel from the surface to the drill bit and return to the surface with cuttings. As an example, the markers are used to determine the flow of cuttings within the wellbore.

Abstract: The invention relates to a tool for use in wellbore drilling, suitable for use with a drill string for drilling a wellbore having an inner wall, the tool comprising means for generating particles of solid material from the formed inner wall of a drilled wellbore, and means for directing the generated particles to the inner wall of the wellbore and a method of forming a layer of solid particles on the inner wall of a wellbore drilled by such a drill string.

Abstract: A rheometer is provided for measuring rheological properties of a filtercake. The rheometer comprises a cell for containing a pressurised fluid supporting a particulate suspension. The cell has two outlets for removing the fluid from the cell. The cell further has a respective foraminous body at each outlet, such that the particulate suspension forms a filtercake on a surface of each foraminous body as pressurised fluid filters through the body when the fluid passes from the cell to the respective outlet. The foraminous bodies are translatable relative to each other, such that the filtercakes formed on said surfaces can be approached to form a unified filtercake. The foraminous bodies are also rotatable relative to each other. The rheometer further comprises a torque sensor for measuring a torque required to rotate the foraminous bodies relative to each other. The measured torque is indicative of one or more rheological properties of the unified filtercake.

Abstract: Downhole systems and methods including tags configured to provide distinguishable identifiers are set for selective release to a subsurface location. Sources/sensors in the wellbore are activated to detect the tags at a subsurface location, and signal data associated with the detected tags is conveyed to the surface.

Abstract: A method of constructing a borehole drilled with a drilling apparatus (16), the method comprises: connecting a flexible tubular liner sleeve (22) around the outside of the drilling apparatus and connecting the sleeve around an upper opening of the borehole so as to pass into the borehole; progressively extending the sleeve into the borehole as drilling progresses while maintaining connection to the drilling apparatus and borehole opening; at a predetermined point in the drilling, expanding the sleeve so as to contact the borehole wall; and setting the sleeve so as to be fixed to the borehole wall after expansion. Apparatus for use in such a method comprises: a flexible, expandable sleeve (22); a first connector for connecting the sleeve around the outside of a drilling assembly; and a second connector for connecting the sleeve around the opening of the borehole; wherein the sleeve is arranged to extend through the borehole between the connectors as drilling progresses.

Abstract: Downhole systems and methods including tags configured to provide distinguishable identifiers are set for selective release to a subsurface location. Sources/sensors in the wellbore are activated to detect the tags at a subsurface location, and signal data associated with the detected tags is conveyed to the surface.

Abstract: A technique that is usable with a well includes deploying a sensing device on a drill string and communicating with the sensing device during a plug cementing operation over a wired infrastructure of the drill string. The technique includes controlling the plug cementing operation in response to the communication.

Abstract: Embodiments of the present invention provide systems and methods for lining a wellbore. In certain aspects, the systems and methods comprise providing a fluid composition that is solidifiable or gellable on exposure to actinic radiation of a predetermined wavelength at the wall of open-hole wellbore and providing actinic radiation at the predetermined wavelength to solidify or gel the composition.

Abstract: A water based drilling fluid contains as additive one or more alkyl ethoxylates having the formula RO(CH2CH2O)nH; wherein: R is a C16-22alkyl group (preferably R is aliphatic and more preferably R is linear), and n is an integer in the range 2-30. The fluid further contains one or more viscosifying agents, and is substantially clay-free.

Abstract: Additive for a drilling fluid to block drilling-induced or pre-existing rock fractures comprising polymeric granules with a diameter distribution peak between 1000 and 200 microns and an average resiliency of at least 10% rebound after compression by a load of 200 N and uses thereof.

Abstract: The present invention provides a method of drilling a hydrocarbon well using a drillstring adapted to provide a continuous or quasi-continuous contact with the wall of the well such that at least of section the well a compacting force is exerted on filter cake deposited thereon; circulating a drilling mud through the borehole during the drilling operation such that a filter cake is deposited on the borehole wall by the drilling mud, the filter cake being compacted by contact with the drillstring, including, before the drilling mud enters the borehole a conditioning additive in the drilling mud, the additive conditioning the filter cake upon the contact with the drillstring to increase the yield strength of the filter cake.

Abstract: Additives for drilling fluids, in particular for water-based drilling fluids are described which when added to the fluid at levels of up to 10% weight by volume reduces the accretion and bit-balling tendencies of shale cuttings exposed to said fluids. The additives are based on phosphonate chemistry, and are of the general class (I), wherein R, R? and R? are radicals exclusively containing H atoms or combinations of H, C, O or P atoms up to a maximum of 100 atoms.

Abstract: Additives for drilling fluids, in particular for water-based drilling fluids are described which when added to the fluid at levels of up to 10% weight by volume reduces the accretion and bit-balling tendencies of shale cuttings exposed to said fluids. The additives are based on phosphonate chemistry, and are of the general class (I), wherein R, R′ and R″ are radicals exclusively containing H atoms or combinations of H, C, O or P atoms up to a maximum of 100 atoms.

Abstract: The use of polymer latices is described for fluid loss control in water-based drilling fluids. The latices used are water insoluble. The latices are essentially non-swelling in an aqueous solution. The latices are selected from known latices such that they are absorbed within a filter cake building up at the interface between the wellbore and porous formations in essentially the same state as they are in the aqueous drilling fluid during circulation.

Abstract: The present invention relates to a process used in a well for controlling the filtration of a drilling, a completion or a workover fluid set in a well. The process comprises adding a predetermined amount of at least one hydrophobically modified cellulose derivative. In a variant of the invention, the cellulose derivative is a hydrophobically modified hydroxyethylcellulose. The invention further relates to a drilling, a completion or a workover fluid including at least one hydrophobically modified cellulose derivative, for example hydrophobically modified hydroxyethylcellulose and notably viscosifiers such as polymers or reactive clay.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.