Abstract: A method of progressively gravel packing is provided which enables individual sections of a continuous wellbore portion to be gravel packed in succession. In a described embodiment, multiple well screens are positioned in a wellbore. A continuous portion of the wellbore is isolated using, for example, one or more packers, with the well screens being disposed in the isolated portion. The isolated wellbore portion is then progressively gravel packed in successive individual predetermined sections of the isolated wellbore portion.

Abstract: Screen assemblies (40, 42) and a single trip method for selectively fracturing multiple formations (14, 16) traversed by a wellbore (32) are disclosed. Each formation (14, 16) has a screen assembly (40, 42) having a plurality of valves (60, 66) positioned adjacent thereto. During the treatment process, the formations (14, 16) are selectively treated with a treatment fluid that is pumped into the interior of the adjacent screen assembly (40, 42). The valves (60, 66) of the respective screen assemblies (40, 42) progressively allow the treatment fluid to exit from the interior to the exterior of the screen assemblies (40, 42) such that each formation (14, 16) is progressively fractured.

Abstract: An apparatus (38) and method for progressively gravel packing an interval of a wellbore (32) is disclosed. The apparatus (38) comprises a sand control screen (52) that is positioned within the wellbore (32) and a tubular member (42) that is disposed within the wellbore (32) forming a first annulus (56) with the sand control screen (52) and a second annulus (58) with the wellbore (32). The tubular member (42) initially prevents fluid communication between the first annulus (56) and the second annulus (58). Once the gravel packing operation begins, however, the tubular member (42) selectively allows fluid communication from the first annulus (56) to the second annulus (58) by progressively establishing fluid communication between the first annulus (56) and the second annulus (58) from a first end of the interval (48) to a second end of the interval (48).

Abstract: An apparatus and method for progressively treating an interval of a wellbore (32) is disclosed. The apparatus comprises a sand control screen (138) that is eccentrically positioned within the wellbore (32) and a fluid delivery tubular (140) that is disposed within the wellbore (32) adjacent to the sand control screen (138). During a treatment process when a treatment fluid is pumped into the fluid delivery tubular (140), the fluid delivery tubular (140) progressively allows the treatment fluid to exit from the interior of the fluid delivery tubular (140) to the exterior of the fluid delivery tubular (140) from a first end (46) of the interval (48) to a second end (44) of the interval (48) to progressively treat the interval (48) of the wellbore (32).

Abstract: A screen assembly (38) and method for progressively treating an interval (48) of a wellbore (32) is disclosed. The screen assembly (38) comprises a sand control screen (40) that is positioned within the wellbore (32) and a plurality of diverter members(42) that are positioned along the sand control screen (40). During a treatment process when a treatment fluid is pumped into the interior of the sand control screen (40), the diverter members(42) progressively allow the treatment fluid to exit from the interior of the sand control screen (40) to the exterior of the sand control screen (40) from a first end (46) of the interval (48) to a second end (44) of the interval (48) to progressively treat the interval (48) of the wellbore (32).

Abstract: A method of progressively gravel packing is provided which enables individual sections of a continuous wellbore portion to be gravel packed in succession. In a described embodiment, multiple well screens are positioned in a wellbore. A continuous portion of the wellbore is isolated using, for example, one or more packers, with the well screens being disposed in the isolated portion. The isolated wellbore portion is then progressively gravel packed in successive individual predetermined sections of the isolated wellbore portion.

Abstract: An apparatus (38) and method for progressively gravel packing an interval of a wellbore (32) is disclosed. The apparatus (38) comprises a sand control screen (52) that is positioned within the wellbore (32) and a tubular member (42) that is disposed within the wellbore (32) forming a first annulus (56) with the sand control screen (52) and a second annulus (58) with the wellbore (32). The tubular member (42) initially prevents fluid communication between the first annulus (56) and the second annulus (58). Once the gravel packing operation begins, however, the tubular member (42) selectively allows fluid communication from the first annulus (56) to the second annulus (58) by progressively establishing fluid communication between the first annulus (56) and the second annulus (58) from a first end of the interval (48) to a second end of the interval (48).

Abstract: A tortuous path sand control screen (40) for reducing the velocity of particles (66) traveling therethrough is disclosed. The tortuous path sand control screen (40) comprises a base pipe (42) and a screen wire (48) wrapped therearound having turns (50, 52, 54) which extend along at least a portion of the length of the base pipe (42) forming gaps between adjacent turns (50, 52). The screen wire has a profile (62, 64) that reduces the velocity of the particles (66) traveling through the gaps, thereby minimizing erosion of the tortuous path sand control screen (40).

Abstract: A screen or filter assembly is described as well as improved methods of affixing such assemblies to a portion of an oil or gas production assembly. A nonrigid attachment for reversibly securing a tubular screen to a portion of a production string is disclosed which significantly reduces the risk of the connection between the screen and the production nipple from being broken. In a preferred embodiment, an end cap is described having a projecting lip which secures one end of the screen body to a perforated sub. A removable threaded retaining sleeve is used to secure the other end of the screen body to the perforated sub. A compression ring is associated with the threaded connector to assist in securing the screen body end. A pair of deformable rings are placed adjacent each of the screen body ends to absorb service loads. The screen assembly may be subjected to operational tensile and compressive stresses and thermal expansions and contractions without significant risk of connection failure.

Abstract: Apparatus for inspecting well screens and associated methods of inspecting well screens provides accurate and convenient inspection of well screens. The methods and apparatus may also produce data useful in designing well completions. In a described embodiment, a method of inspecting a filtering portion of a well screen includes utilizing a light sensor to measure the intensity of light transmitted through the filtering portion. An array of fiber optic lines is arrayed about the filtering portion and interconnected to the sensor. A light source within the filtering portion and the array of fiber optic lines are displaced simultaneously along the filtering portion. The sensor is connected to an instrument, which indicates whether the measured light intensity is within an acceptable range. Furthermore, the measured light intensity may be related to a hydraulic resistance of the filtering portion.

Abstract: A progressive gap sand control screen comprising a plurality of parallel ribs spaced around an axis and a screen wire wrapped around the plurality of ribs having turns which extend along the length of the plurality of ribs such that adjacent turns have gaps therebetween, the gaps forming a gap profile in which the gaps near the upper end of the sand control screen are narrower than the gaps near the lower end of the sand control screen, the width of the gaps near the upper end of the sand control screen being less than the diameter of the particles which cause erosion, the gap profile includes a variable gap section near the upper end of the sand control screen and a constant gap section below the variable gap section, the variable gap section having a linear profile, a step type profile, or a nonlinear profile.

Abstract: A drainage pipe section for a horizontal subterranean well has a base pipe coaxially circumscribed by a tubular structure having a longitudinally intermediate portion defined by a sand screen assembly. An annular flow passage is formed between the base pipe and the tubular structure and communicates with the interior of the base pipe via base pipe sidewall openings positioned inwardly adjacent opposite end portions of the tubular structure. Annular adjustable flow control members having variable length labyrinth passages recessed into their outer sides are coaxially interposed in the annular flow passage between the opposite ends of the sand screen assembly and the base pipe sidewall openings. The flow control members are sealed within the annular flow passage by means of a rubber coating adhered to their outer side surfaces, and an adhesive type sealant material injected into annular spaces between the flow control members and facing portions of the base pipe.

Abstract: An apparatus and method for continuously mixing well treatment fluids, such as fracturing gels and the like. Dry polymer is fed into a metering feeder which accurately meters the rate of polymer fed into a water spraying mixer. A vent is provided so that air can enter with the polymer as necessary. Water, with or without a buffering compound therein, is flowed through a water inlet of the mixer. The water is jetted into a spiraling flow pattern through which the polymer falls and is substantially wetted. Auxiliary water inlets may be used to add additional water to the water-polymer slurry to increase mixing energy and increase the amount of slurry produced. The slurry is discharged into a mixing tank with an agitator and then into a holding tank. The slurry may also pass through a shear device to further increase the rate of viscosification of the slurry.

Abstract: A core holder for testing core permeability includes a modular sleeve comprising a series of sleeve segments aligned longitudinally. Port rings positioned between the sleeve segments have radial holes to allow conditions within the core-receiving cavity formed by the sleeve segments and the port rings to be monitored from outside the core holder. The port rings and the sleeve segments are disposed within a housing, and spacer rings are received about the sleeve segments to support the sleeve segments and port rings within the housing. Conditions within the modular sleeve may be monitored through instruments connected to holes in the housing communicating with the holes in the port rings.

Abstract: An injection manifold for use in injecting fluid into a well and method of use. Several embodiments of the apparatus are shown. In each embodiment, a bypass valve is used to control the discharge pressure of a pump, and a throttling valve is used to control the fluid injection flow rate to the well in response to a flow rate measured by a flow meter. In a first embodiment, the throttling is carried out manually. In a second embodiment, the throttling is carried out automatically by a controller which compares a flow rate signal from the meter with a predetermined flow rate set point and sends a corresponding output signal to an actuator of the throttling valve. A third embodiment is a combination manifold which may also be used for flowback tests from the well. In this third embodiment, the electronic controller may also be used to control the flow rate during the flowback test in response to a flow rate signal from the flow meter. A method of injecting fluid into a well using the apparatus is also disclosed.

Abstract: A protective cover comprises a substantially circular cover including a center shear disc surrounded by an annular outer portion, mounted in the fluid end of a plunger-type high pressure pump. The cover is held in place by the retainer assembly of the present invention, which is secured to the fluid end. When subjected to a compressive load by the plunger in excess of a predetermined limit, the shear disc shears from the outer portion along an arcuate boundary of reduced wall thickness between the shear disc and outer portions and the sheared disc is propelled by the pressure into the retainer assembly, striking a plug which in turn forces an impact disc into the end of the retainer, which includes a substantially circular recess therein of lesser diameter than the impact disc. The impact disc is thus sheared as the inner portion thereof enters the retainer recess, the energy from the shear disc being thereby substantially dissipated without harm to the retainer.

Abstract: The present invention comprises a method and apparatus for maintaining a liquified gas such as CO.sub.2 or N.sub.2 in a liquid state prior to its introduction into the suction of a positive displacement pump such as is commonly employed in high pressure well stimulation work in the petroleum industry. A heat exchanger, preferably referred to as a passive booster, is placed in the liquified gas feed line between the gas source and the positive displacement pump. Gas is introduced into the shell side of the passive booster from a chamber in the tube side through a variable orifice throttling valve which, through the Joule-Thomson Effect, drops the temperature of the gas in the shell to provide refrigeration for the main liquified gas flow through the tube side of the passive booster. Flow through the variable orifice valve may be controlled manually or automatically. A back pressure valve on the shell side of the passive booster may be employed to prevent solid formation if one is employing liquified CO.sub.