Abstract: An invert emulsion fluid may include a oleaginous external phase, a nonoleaginous internal phase, wherein a ratio of the oleaginous external phase to nonoleaginous internal phase is less than 55:45, a emulsifier, a particulate weighting agent dispersed in the non-oleaginous internal phase, and a viscosifier stabilizing the dispersion of the particulate weighting agent in the non-oleaginous internal phase.

Abstract: Methods for drilling a wellbore into a subterranean formation include preparing a drilling fluid and circulating the drilling fluid in the wellbore while drilling in the subterranean formation, forming a filtercake from the drilling fluid, creating or encountering one or more fractures in the subterranean formation while drilling, and allowing a portion of the filtercake formed to at least partially seal the one or more fractures while continuing the drilling.

Abstract: Methods for drilling a wellbore into a subterranean formation include preparing a drilling fluid and circulating the drilling fluid in the wellbore while drilling in the subterranean formation, forming a filtercake from the drilling fluid, creating or encountering one or more fractures in the subterranean formation while drilling, and allowing a portion of the filtercake formed to at least partially seal the one or more fractures while continuing the drilling.

Abstract: An invert emulsion fluid may include a oleaginous external phase, a nonoleaginous internal phase, wherein a ratio of the oleaginous external phase to nonoleaginous internal phase is less than 55:45, a emulsifier, a particulate weighting agent dispersed in the non-oleaginous internal phase, and a viscosifier stabilizing the dispersion of the particulate weighting agent in the non-oleaginous internal phase.

Abstract: A drilling fluid for use when drilling a borehole includes solid polymeric objects as a lost circulation additive. The objects have an overall size extending at least 0.5 mm in each of three orthogonal dimensions have a shape such that each object has one or more edges, points or corners and/or comprises a core portion with a plurality of projections which extend out from the core portion. The objects may be moulded, 3D-printed or chopped from larger pieces of polymer by granulating machinery. Shapes with edges, points, corners or projections assisting the objects in lodging within and bridging a fracture encountered or formed while drilling.

Abstract: A fluid used in a borehole containing suspended solid objects made by an additive manufacturing process. An additive process of solidifying a liquid composition at a succession of selected locations within a workspace, in accordance with a digital design allows a wide variety of shapes to be made. The fluid may be a drilling fluid or a borehole treatment fluid used prior to cementing and the objects may act, possibly in conjunction with other solids, to block loss of fluid into fractures in the formation around the borehole.

Abstract: Application of a photocurable lining to a downhole fixed surface surrounding the axis of a wellbore is carried out by skimming an applicator over the downhole surface while delivering a porous tape impregnated with a photocurable liquid composition between the applicator and the downhole surface so that the tape lies on the downhole surface and directing light of wavelength in a range from 100 nm to 1500 nm onto the curable composition impregnating the tape so as to initiate curing of the composition and thereby attach the tape to the downhole surface.

Abstract: Embodiments of the present invention provide compositions and methods for lining a wellbore. In certain aspects, the compositions 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. The predetermined wavelength lies in a range from 100 nm to 1500 nm.

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. The predetermined wavelength lies in a range from 100 nm to 1500 nm.

Abstract: A method of lining tubing within a wellbore comprises applying a polymerisable fluid composition containing a photoinitiator to the interior surface of that tubing and initiating polymerisation of the composition by exposing it to actinic radiation, suitably light or ultraviolet with wavelength 250 to 800 nm. The composition is preferably stable against heat but polymerises quickly when exposed to the actinic radiation. The composition may be spread onto the tubing and exposed to actinic radiation as soon as it has been spread into a layer, suitably with a tool which skims the tubing surface with applicator pads for dispensing and spreading the composition, immediately followed by exposing the spread composition to actinic radiation. A second option is that the composition is provided as a sleeve which is expanded against the tubing, exposure to actinic radiation preferably then being achieved using light guides or light emitting diodes within the sleeve.

Abstract: A tool for use in wellbore drilling that is suitable for use with a drill string for drilling a wellbore having an inner wall. The tool comprises a cylindrical abrasion surface for contacting the inner-wall and generating particles of solid material, and a smearing device coupled with the drill string for applying radial and circumferential force to smear the generated particles onto the inner wall of the wellbore.

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: A system and method for releasing a marker within a wellbore. 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: Embodiments of the present invention provide compositions and methods for lining a wellbore. In certain aspects, the compositions 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. The predetermined wavelength lies in a range from 100 nm to 1500 nm.

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. The predetermined wavelength lies in a range from 100 nm to 1500 nm.

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: 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: 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: A method of lining tubing within a wellbore comprises applying a polymerisable fluid composition containing a photoinitiator to the interior surface of that tubing and initiating polymerisation of the composition by exposing it to actinic radiation, suitably light or ultraviolet with wavelength 250 to 800 nm. The composition is preferably stable against heat but polymerises quickly when exposed to the actinic radiation. The composition may be spread onto the tubing and exposed to actinic radiation as soon as it has been spread into a layer, suitably with a tool which skims the tubing surface with applicator pads for dispensing and spreading the composition, immediately followed by exposing the spread composition to actinic radiation. A second option is that the composition is provided as a sleeve which is expanded against the tubing, exposure to actinic radiation preferably then being achieved by means of light guides or light emitting diodes within the sleeve.