Showing papers on "Annulus (oil well) published in 2004"

Interaction of rim seal and annulus flows in an axial flow turbine

Abstract: A combined computational fluid dynamics (CFD) and experimental study of interaction of main gas path and rim sealing flow is reported. The experiments were conducted on a two stage axial turbine and included pressure measurements for the cavity formed between the stage 2 rotor disc and the upstream diaphragm for two values of the diaphragm-to-rotor axial clearance. The pressure measurements indicate that ingestion of the highly swirling annulus flow leads to increased vortex strength within the cavity. This effect is particularly strong for the larger axial clearance. Results from a number of steady and unsteady CFD models have been compared to the measured results. Good agreement between measurement and calculation for time-averaged pressures was obtained using unsteady CFD models, which predicted previously unknown unsteady flow features. This led to fest response pressure transducer measurements being made on the rig, and these confirmed the CED prediction.

Sand control completion having smart well capability and method for use of same

Abstract: A sand control completion (100) for installation in a wellbore (102) includes first and second packers (114, 116) that define a first zone (110) in the wellbore (102). A production tubing (120) extends substantially through the first zone (110). Positioned between the first and second packers (114, 116) are a sand control screen (130), an inflow control valve (122) and a crossover valve (126). The sand control screen forms a first annulus (152) with the production tubing (120) and a second annulus with the wellbore (102). The inflow control valve (122) is operable to selectively allow and prevent fluid communication between the first annulus (152) and the interior of the production tubing (120). The crossover valve (126) is operable to selectively allow and prevent fluid communication between the production tubing (120) and the second annulus.

Annular isolators for tubulars in wellbores

Abstract: The present disclosure addresses apparatus and methods for forming an annular isolator in a borehole after installation of production tubing. A first deployable annular isolator is carried on tubing as it is positioned in a borehole. An annular isolator forming material is placed in the annulus around the first deployable isolator. The first isolator is then deployed into the material in the annulus to form a combined isolator. The annular isolator forming material is carried in a compartment in the tubing and forced from the compartment into the annulus. A second deployable isolator may be deployed before placing the material in the annulus to resist annular flow of the material before the first isolator is deployed. The second isolator may be deployed by material from the compartment. A second compartment may be provided to deploy the first isolator.

Flow structure of subcooled boiling flow in an internally heated annulus

Abstract: Local measurements of flow parameters were performed for vertical upward subcooled boiling flows in an internally heated annulus. The annulus channel consisted of an inner heater rod with a diameter of 19.1 mm and an outer round pipe with an inner diameter of 38.1 mm, and the hydraulic equivalent diameter was 19.1 mm. The double-sensor conductivity probe method was used for measuring local void fraction, interfacial area concentration, and interfacial velocity. A total of 11 data were acquired consisting of four inlet liquid velocities, 0.500, 0.664, 0.987 and1.22 m/s and two inlet liquid temperatures, 95.0 and 98.0 degrees Celsius. The constitutive equations for distribution parameter and drift velocity in the drift-flux model, and the semi-theoretical correlation for Sauter mean diameter, namely, interfacial area concentration, which were proposed previously, were validated by local flow parameters obtained in the experiment.

Methods for increasing production from a wellbore

Abstract: The present invention generally relates to a method for recovering productivity of an existing well First, an assembly is inserted into a wellbore, the assembly includes a tubular member for transporting drilling fluid downhole and an under-reamer disposed at the end of the tubular member Upon insertion of the assembly, an annulus is created between the assembly and the wellbore Next, the assembly is positioned near a zone of interest and drilling fluid is pumped down the tubular member The drilling fluid is used to create an underbalanced condition where a hydrostatic pressure in the annulus is below a zone of interest pressure The under-reamer is activated to enlarge the wellbore diameter and remove a layer of skin for a predetermined length During the under-reaming operation, the hydrostatic pressure is maintained below the zone of interest pressure, thereby allowing wellbore fluid to migrate up the annulus and out of the wellbore After the under-reaming operation, back-reaming may be performed to remove any excess wellbore material, drill cuttings and fines left over from the under-reaming operation and to ensure no additional skin damage is formed in wellbore Upon completion, the under-reamer is deactivated and the assembly is removed from the wellbore

Well screen primary tube gravel pack method

Abstract: A method for performing a gravel pack and/or frac pack by pumping down small tubes connected to nozzle chambers installed in the well screen in an open or cased hole of an oil, gas or water well. The well employs an open-hole wellbore adjacent to a substantial portion of an unconsolidated or poorly consolidated subterranean oil or gas reservoir. A well screen is located inside the open-hole wellbore forming an annulus between the open-hole and the well screen. One or more conduits are positioned in the annulus formed by the base pipe and the outer surface of the screen, and connected to corresponding exit nozzle chambers positioned at different levels on the screen. These are the primary conduits for the solids ladened fluid to be transported to the exit nozzles attached to the well screen member that provide fluid communication between the conduit and the annulus between the open -hole and the well screen. The solids ladened fluid is pumped to and out through the exit nozzles as the fluid dehydrates the solids (gravel) are deposited on the well screen as the fluid passes through leaving the annulus packed with gravel. This method is also applicable to gravel packing and/or frac packing in a cased wellbore with perforations for fluid communication between the cased wellbore and a substantial portion of an unconsolidated or poorly consolidated oil or gas reservoir.

Hydrodynamic, down-hole anchor

Abstract: A method of removably anchoring well tubing in a well bore may include selecting a well having a bore diameter and an anchor positioned therein. The anchor may have a housing defining an anchor diameter and extension members extending therefrom toward the bore diameter. The bore diameter and anchor diameter may be spaced apart a distance defining an annulus therebetween and extending along the well. A tool sized to cut substantially exclusively within the annulus may be selected. The tool may be positioned within the annulus, rotated, and advanced to drive past the housing to remove the extension members between the housing and the bore diameter to free the anchor.

Reverse circulation cementing system and method

Abstract: A system and method of cementing in an annulus formed between a casing and the wall of a well bore, wherein a foamed cement is introduced into the upper portion of the annulus, directed downwardly through the annulus and back up into the casing, and then displaced back down the casing and into the annulus.

Reverse circulation cementing process

Abstract: A method of cementing a casing in a wellbore with a tool having a plurality of holes (21) therethrough connected at a lower end of the casing. A plurality of stoppers (30) are pumped in a leading edge of a cement slurry (13) down an annulus (14) between the casing and the wellbore to the tool where the stoppers engage the holes to hold the cement slurry in the annulus until the cement slurry hardens. A valve maybe incorporated with the stopper catch tool (20). Stoppers and holes may have various shapes and centrifugal pump (60) may be used.

Methods of initiating a fracture tip screenout

Abstract: Methods of initiating a fracture tip screenout, that comprise pumping an annulus fluid into an annulus, between the subterranean formation and a work string disposed within a wellbore penetrating the subterranean formation, at an annulus flow rate; and reducing the annulus flow rate below a fracture initiation flow point so that the fracture tip screenout is initiated in the one or more fractures in the subterranean formation, are provided. Also provided are methods of fracturing a portion of a subterranean formation and methods of estimating a fracture initiation flow point.

Ultrasonic cement scanner

Abstract: An acoustic borehole logging system for parameters of a well borehole environs. Full wave acoustic response of a scanning transducer is used to measure parameters indicative of condition of a tubular lining the well borehole, the bonding of the tubular to material filling an annulus formed by the outside surface of the tubular and the wall of the borehole, the distribution of the material filling the annulus, and thickness of the tubular. A reference transducer is used to correct measured parameters for variations in acoustic impedance of fluid filling the borehole, and for systematic variations in the response of the scanning transducer. Corrections are made in real time. The downhole tool portion of the logging system is operated essentially centralized in the borehole using a centralizer that can be adjusted for operation in a wide range of borehole sizes.

Underbalanced drilling method and apparatus

Abstract: A method of drilling well bore ( 20 ) through and below permeable formation ( 22 ) bearing such fluids as gas, oil, water wherein drill cuttings may be evacuated by formation fluid ( 23 ) being produced through the drill string ( 26 ) either by decreasing well head back pressure or by gas lift. Production rate is kept substantially stable by operating choke valves ( 140 ) and ( 142 ) placed after separator ( 52 ). Formation fluid being produced while drilling may be pumped into well bore ( 20 ) through annulus ( 31 ) or utilized. The unique injector included in the drill string provides for possibility to pump simultaneously into annulus ( 31 ) lifting gas and produced liquid and may be operated from the surface. A method and system ( 90 ) comprising a plurality of special 3-way valves included in drill string ( 26 ), are provided for making connections without interrupting flushing the well bore.

Fluid and Solids Flow Affecting the Solids Circulation Rate in Spouted Beds with a Draft-Tube

Abstract: In a spouted bed, the gas flow rates cannot be changed independently in either the spout or the annulus. In this study, an experimental spouted bed equipped with a draft-tube was made in such a way that each of the gas flow rates can be changed independently. The effect of the gas flow rate in the spout or in the annulus on the circulation rate of solids was examined for the three types of spouted bed. The relation between the solids circulation rate and the average gas velocity in the annulus differs among these three types of spouted beds. In the spouted bed with a gas inlet nozzle, the solids circulation rate initially sharply decreased with the average gas velocity in the annulus. It was found that an eddy motion of solid particles caused this sharp decrease in the solids circulation rate. The fluid flow that caused this eddy motion in the solids was confirmed by using a two-dimensional water flow model.

Extended flashback annulus in a gas turbine combustor

Abstract: An extended flashback annulus ( 520 ) is formed between an exterior surface ( 506 ) of a shroud or casing ( 508 ) associated with a main swirler assembly inner body ( 500 ) or other fuel/air mixing device and the inner surface ( 514 ) of an annulus casting ( 510 ) which are in operational relationship with one another in a gas turbine combustor assembly. The extended flashback annulus ( 520 ) is capable of forming an extended protective cylindrical air barrier ( 550 ) that extends farther into the combustion zone, this barrier being more robust and providing for the reduction or prevention of flashback to the baseplate and other heat-susceptible upstream components.

Junk basket and method

Abstract: Junk basket 10 is provided for collecting debris from a wellbore cleaning operation, and includes a central mandrel 14 having a throughbore 16 and an outer shell 24 defining a generally annular junk space 40 . The outer shell 24 may be configured such that the annulus 27 includes a reduced portion 28 . Flow holes 30 in the outer shell are preferably angled substantially upward, and are positioned to discharge fluid to the annulus 27 . According to a method of the invention, fluid is passed from an upper tubing string, through the central mandrel, into the wellbore and upward through the annulus and past the flow holes, thereby reducing pressure of flow past the well holes to pass fluid from the junk space through the flow holes.

System and method for fracturing a hydrocarbon producing formation

Abstract: A system and method for fracturing a hydrocarbon producing formation in which a fracturing tool is inserted in a wellbore adjacent the formation, and fracturing fluid is introduced into the annulus between the fracturing tool and the wellbore and flows to the formation.

A method and device for controlling drilling fluid pressure

Abstract: A method and device for controling drilling fluid pressure during subsea drilling, where drilling fluid is pumped down into a borehole (15) and then flows back to a drilling rig (1) via the lined and/or unlined sections of the borehole (15) and a liner (14), wherein the drilling fluid pressure is controlled by pumping drilling fluid out of the liner (14) at the seabed, and where the liner (14) annulus (30) above the drilling fluid is filled with a riser fluid having a density different from that of the drilling fluid.

Inflate control system for inflatable straddle stimulation tool

Abstract: A method and apparatus for controlling inflation and deflation of spaced inflatable packer elements of a straddle stimulation tool within a well casing of a well. A straddle stimulation tool is positioned by tubing at a desired location within the well casing. Fluid is pumped through the tubing and tool at a rate inflating the spaced inflatable packer elements within the well casing and establishing an annulus interval. The inflation control retains pressure within the inflated packer elements and permits the flow of stimulation fluid into the annulus interval for stimulation of the formation. After completion of well stimulation, the packer element pressure control is moved to a packer equalizing position by tension applied via the tubing to equalize packer pressure with casing annulus pressure, deflating the packer elements and permitting conveyance of the straddle stimulation tool within the well casing by the tubing string.

Fluids comprising reflective particles and methods of using the same to determine the size of a wellbore annulus

Abstract: In embodiments, methods of determining a size of an annulus in a wellbore include: (a) displacing a fluid comprising reflective particles downhole and up through the annulus, wherein the reflective particles make a front end of the fluid visible as it exits the wellbore; (b) determining a total volume of the fluid displaced into the wellbore by detecting the reflective particles exiting the wellbore; and (c) calculating the size of the annulus based on that total volume of the fluid. The fluid may include a drilling fluid, a cement slurry, a spacer fluid, or combinations thereof. The reflective particles may include polymeric beads. In additional embodiments, drilling fluids, spacer fluids, cement slurries and combinations thereof comprise an effective amount of reflective particles to ensure that the fluids are visible when they exit a wellbore.

Method and apparatus for testing and treatment of a completed well with production tubing in place

Abstract: A method and apparatus is used to test and/or treat individual production zones of a well in conjunction with a conventional coiled tubing unit. This method and apparatus allows testing and treatment of a well with production tubing in place. The return flowpath for formation fluids and/or treatment fluids is through the annulus between the coiled tubing and the production tubing. The preferred embodiment uses straddle packers, but alternative embodiments may use only a single inflatable packer.

Cuttings injection and annulus remediation systems for wellheads

Abstract: A wellhead assembly has an inner wellhead that lands in an outer wellhead, the inner wellhead having first and second internal passages. Each passage has an upper opening at the outer surface of the inner housing and a lower opening at the inner surface. An external shoulder of a casing hanger lands on an internal shoulder of the inner housing, the lower opening of the first passage being below the internal shoulder, the lower opening of the second passage being above the internal shoulder. The casing hanger has a substantially-vertical passage located in its sidewall, an upper port registering with the lower opening of the second passage, a lower port being located below the external shoulder for communicating with the annulus. Valve assemblies at the upper openings control the flow of heavy fluid injected into a casing annulus through the second passage and of cuttings injected into the annulus through the first passage.

Ported velocity tube for gas lift operations

Abstract: An apparatus for use with a packer set within a well bore comprises a first flow path providing fluid communication between the well bore above the packer and the well bore below the packer, and a second flow path. A system for gas lifting fluids from a well bore with a packer set therein defining an upper portion and a lower portion of the well bore comprises production tubing, the packer, and a ported velocity tube. A method for producing a fluid from a well bore zone below a set packer disposed in a production tubing comprises injecting a gas into a well bore annulus formed by the production tubing, flowing the gas downwardly through the packer, jetting the gas into the well bore zone, and flowing the fluid upwardly through the packer into the production tubing.

Downhole completion system and method for completing a well

Abstract: A system for completing a well having casing ( 34 ) includes a perforating assembly ( 38 ) and a tubing string assembly ( 40 ). The tubing string assembly ( 40 ) including a pair of seal assemblies ( 56, 74 ), a production screen assembly ( 58 ) and a ported sleeve ( 66 ) positioned between the seal assemblies ( 56, 74 ) and a live annulus screen assembly ( 76 ) positioned uphole of the seal assemblies ( 56, 74 ). The perforating assembly ( 38 ) is operated to perforate the well and is then released downhole. The tubing string assembly ( 40 ) is then repositioned such that the production screen assembly ( 58 ) is located proximate the perforated interval ( 14 ) so that when the well is hydraulically fractured with a treatment slurry that is pumped through the ported sleeve ( 66 ), the formation reaction to the fracturing is monitored by obtaining pressure readings in the annulus in fluid communication with the live annulus screen assembly ( 76 ).

Method for growth of a hydraulic fracture along a well bore annulus and creating a permeable well bore annulus

Abstract: A method for growth of a hydraulic fracture or a tall frac is described wherein the tall frac is disposed next to a well bore using a sandpacked annulus. Also, a method for creating a permeable well bore annulus is disclosed. The method for creating the tall frac includes creating a linear-sourced, cylindrical stress field by maneuvering the intersection of two independent friction-controlled pressure gradients of a frac pad fluid. The intersection of these two frac pad fluid pressure gradients can be controlled when the frac pad fluid traverses along a well bore sandpacked annulus. The first pressure gradient is created by controlling the fluid flow rate and the consequent, friction pressure loss in the frac pad fluid flow through a portion of the sandpacked annulus, located above the top of the upwardly propagating tall frac hydraulic fracture. The first pressure gradient must be significantly greater than the average gradient of the formation, frac-extension pressure gradient. The second pressure gradient is created by the friction loss of the volume flow rate of the frac pad fluid flowing through the combined parallel paths of the sandpacked annulus and the open hydraulic fracture which is propagating outward in the adjacent rock formation below the top of the upwardly propagating tall frac. The second pressure gradient, below the top of the upward-propagating tall frac, should be about equal to or less than the average gradient of the formation, frac-extension pressure gradient at this location.

Cementing methods using compressible cement compositions

Abstract: A method of cementing at least two casing strings in a well bore, the method having steps as follows: filling the well bore and the inner diameters of the at least two casing strings with a cement composition, wherein at least a portion of the cement composition is a compressible cement composition; pumping the cement composition from the inner diameters of the at least two casing strings into the annulus, wherein the compressible portion of the cement composition is compressed by the pumping; and permitting the cement composition to set within the annulus.

Method for releasing stuck drill string

Abstract: A method for releasing a drill string stuck against a wall of a well bore due to pressure differential between the hydrostatic pressure of a fluid in the well bore and the pressure of a formation at the point where the drill string is stuck. The method includes injecting a first fluid into the annulus via the drill string and simultaneously injecting a second fluid into the annulus at an upper end of the annulus. The first fluid and the second fluid are injected into the annulus at a volume and rate sufficient to cause at least one of the first fluid and the second fluid to penetrate the formation and increase the pressure of the formation adjacent the well bore so that the pressure of the formation adjacent the well bore is substantially equalized with the pressure of the well bore. A jarring force is simultaneously exerted to the drill string to cause the drill string to release.

Cased borehole investigation apparatus deviates parasitic echoes away from receiver

Abstract: An apparatus for investigating the cement annulus between a steel casing 5 and a borehole wall comprises an acoustic (ultrasonic) transmitter T and receiver R spaced apart and aligned at an angle from the normal to the wall of the casing, in a pitch-catch arrangement. Only a small amount of the emitted acoustic energy is transmitted through the casing to the probe the annulus, so the shape of the tool structure 9 is designed so as to deviate any unwanted parasitic echoes (specular reflections, tool reflections) away from the receiver R. The edge surfaces of the supporting structure 9 are serrated 12 to deviate unwanted signals, and the structure may further be coated in an absorbing material which attenuates unwanted signals. A second receiver may be provided to allow for computation of casing flexural wave attenuation. Deflector plates may also be used to further reduce unwanted waves.