Systems and methods are provided for treating a wellbore using a loop system to heat oil in a subterranean formation contacted by the wellbore. The loop system comprises a loop that conveys a fluid (e.g., steam) down the wellbore via a injection conduit and returns fluid (e.g., condensate) from the wellbore via a return conduit. A portion of the fluid in the loop system may be injected into the subterranean formation using one or more valves disposed in the loop system. Alternatively, only heat and not fluid may be transferred from the loop system into the subterranean formation. The fluid returned from the wellbore may be re-heated and re-conveyed by the loop system into the wellbore. Heating the oil residing in the subterranean formation reduces the viscosity of the oil so that it may be recovered more easily.

Loop systems and methods of using the same for conveying and distributing thermal energy into a wellbore

A system and method for controlling inflow of fluid into a production string. In aspects, the invention provides a downhole sand screen and inflow control device with a gas or water shut-off feature that can be operated mechanically or hydraulically from the surface of the well. The device also preferably includes a bypass feature that allows the inflow control device to be closed or bypassed via shifting of a sleeve. In embodiments, the flow control device can be adaptive to changes in wellbore conditions such as chemical make-up, fluid density and temperature. Exemplary adaptive inflow control devices include devices configured to control flow in response to changes in gas/oil ratio, water/oil ratio, fluid density and/or the operating temperature of the inflow control device. In other aspects of the present invention, inflow control devices are utilized to control the flow of commingled fluids drained via two or more wellbores.

Downhole inflow control device with shut-off feature

A method for completing multi-lateral wells and maintaining selective re-entry into laterals is presented. In accordance with the present invention, a first lateral well is drilled from a primary well bore and a string of external casing packers and a packer bore receptacle are run therein. Once the orientation of the packer bore receptacle is determined, an orientation anchor of a retrievable whipstock assembly is mounted thereto. Thereafter, a second lateral well may be drilled. Once the second lateral well is drilled, the whipstock assembly may be retrieved and replaced with a scoophead diverter assembly which also includes an orientation anchor for mating with the packer bore receptacle. At this time, a string of external casing packers may be run into the second lateral well through the scoophead diverter assembly. Finally, a selective reentry tool is run into the scoophead assembly. The selective re-entry tool includes a diversion flapper for selecting either the first or second lateral well bore. Selective re-entry is desirable for the purpose of performing well intervention techniques. The re-entry tool may be actuated by a device located on a coil tubing work string which may be operated from the surface.

Method for completing multi-lateral wells and maintaining selective re-entry into laterals

Apparatus and methods are disclosed for actively controlling the flow of hydrocarbon fluids from a producing formation at the downhole sand screen. A preferred embodiment of the invention provides a fluid flow annulus within the production tube inside of the screen. In a first flow control configuration, fluid passing through the screen is required to flow along the annulus to find a flow aperture into an interior flow bore. A static flow control device within the annulus between the sand screen and a first flow aperture dissipates flow energy by forcing the flow through a restricted area that helically winds about the flow annulus. Dissipation of the flow energy increases the pressure reduction from the screen into the production bore and reduces the flow velocity. In a second flow control configuration, flow control structure within the flow annulus obstructs all flow along the annulus. A third flow control configuration removes all flow restrictions within the flow annulus.

Sand screen with active flow control and associated method of use

A well packer has a metal seal which seals between the packer mandrel and the casing. The metal seal includes a seal sleeve located on the exterior of the mandrel. The sleeve has an inner wall and an outer wall radially separated by a channel. The inner channel is initially separated from the exterior of the mandrel by a clearance. An energizing ring is sizably mounted to the mandrel for axial movement relative to the mandrel. Initially, the energizing ring will be located at the entrance of the channel. An actuating device moves the energizing ring into the channel, wedging the walls of the seal sleeve apart. The inner wall seals against the mandrel. The outer wall seals against the casing.

Metal seal well packer

An improved packing tool (P1) for sealing spaces between the wall (10) of a wellbore and means (12) defining an elongate member (e.g. tubing) disposed longitudinally in the well bore including a sealing mechanism supportable peripherally about the elongate member and including at least one element (27) containing a shape memory alloy material which maintains a radially contracted condition at below a predetermined temperature--corresponding to the transition temperature of the shape memory alloy--to enable introduction of the sealing mechanism into the well bore and which responds to the temperature by transforming into a radially expanded condition to make sealing contact with the wall of the well bore, establishing a tight metal to metal seal therethrough.

Packing tool apparatus for sealing well bores

Subsurface safety valve assembly (16) for oil wells comprising a valve element (57) and a temperature responsive operator comprising multiple coil springs (69, 70), made of shape memory material, operable in opposing directions for opening and closing the valve element and a ratchet locking mechanism comprising wickers (79) for locking the valve in its open position after removal of the heating which causes shape memory effect movement to such position.

Subsurface well safety valve and control system

An apparatus T 1 for sealing a well tubing 12 including a housing 20, 21, 22 which has a channel 68 communicating with the bore of tubing 12 and a chamber 43 connected with channel 68. A seal 62 is slidably mounted in the housing and is disposed in a retracted open condition in chamber 43 to enable fluid flow through channel 68. AN actuator 41, 42 also disposed in chamber 43, includes a shape memory alloy material which is responsive to the temperature thereof rising to a predetermined level corresponding to the transition temperature of the shape memory alloy for transforming in shape to extend the seal into an extended condition within channel 68, thereby blocking fluid flow therethrough.

Apparatus for sealing a well blowout

Effect of grain size on transformation temperatures in a grain-refined, copper-based, shape-memory alloy☆

A shell and tube heat exchanger had failed its four tubes after just over a year in service. One of these tubes was analyzed in this examination. This heat exchanger is used to transfer heat from steam on the shell side to slurry on the tube side. The tube material was made of SA 249 TP 304L, a standard specification for welded austenitic stainless steel tubes. A failure investigation was carried out on the leaked tubes by performing a number of examinations including visual and macroscopic examination, chemical analysis, metallographic examination, hardness testing and scanning electron microscopy equipped with energy-dispersive spectroscopy analysis. Results of the failure analysis showed that the leaked tubes of the heat exchanger had primarily experienced stress-corrosion cracking (SCC) in the longitudinal direction caused by the combined effects of tensile stress and corrosion. Most of the stress-corrosion cracks initiated at multiple sites of the external surface of the tubes where corrosion pits and other surface defects were present. Formation of surface defects was most likely associated with some excessive contact and/or collision between tube and adjacent tubes or with baffles or other support in the heat exchanger. In the early stage, most of the cracks were not branched, but later continued by cracks branching in transgranular manner. Some of the trace elements found on the fracture surface deposit may have been responsible for the formation of corrosion pits and SCC on the tubes, acting either alone or in combination. In addition, at location close to the multiple parallel cracks in the longitudinal direction, the tube also experienced other multiple parallel cracks, but in its circumferential direction. None of these cracks had reached the internal wall of the tube.

D. N. Adnyana

Papers

Packing tool apparatus for sealing well bores

Subsurface well safety valve and control system

Apparatus for sealing a well blowout

Effect of grain size on transformation temperatures in a grain-refined, copper-based, shape-memory alloy☆

Failure Analysis of Stainless Steel Heat Exchanger Tubes in a Petrochemical Plant