Abstract: A method for maintaining in a computer memory laboratory test records for a plurality of projects, particularly adapted to projects for cementing oil or gas wells, are disclosed. Records of data identifying the plurality of projects and records of test data for the plurality of projects are entered within the computer memory. Data from selected records are compiled in a predetermined report format. More particularly disclosed is a method of designing a cement job for an oil or gas well. This includes receiving into a computer, programmed with records of data in predetermined categories for a plurality of previous cement jobs, a field of search for a selected predetermined category of data pertinent to a cement job being designed. Automatic searching within the computer finds records which contain data within the field of search. These are displayed. Design data are selected in response to the displayed records and the design data are stored in the computer in a record for the cement job being designed.

Abstract: The present invention provides an apparatus for casing a well. The inventive apparatus comprises: an outer casing; an inner casing positionable inside the outer casing; and a squeeze packer assembly incorporatable in the inner casing. The squeeze packer assembly is mechanically operable for sealing the annulus between the inner casing and the outer casing.The present invention also provides a method of installing an inner casing inside an outer casing. The inventive method comprises the steps of: (a) incorporating a mechanically operable squeeze packer assembly in the inner casing and (b) inserting the inner casing into the outer casing.

Abstract: A rotationally operated back pressure valve includes a flapper valve with a sliding stinger tube located thereabove in a housing. An operating mandrel has a lower end portion received in a bore of the housing and the operating mandrel extends upward out of the upper end of the housing. The operating mandrel may be connected to a work string for rotation by the work string. A threaded engagement is provided between the operating mandrel and the stinger tube so that the stinger tube can be selectively moved between a first and second position thereof relative to the housing in response to selected right-hand or left-hand rotation of the operating mandrel relative to the housing. In the first position of the stinger tube it is located above the flapper valve so that the flapper valve closes the housing bore. In the second position of the stinger tube it extends downward through the housing bore past the flapper valve to hold the flapper valve fully open.

Abstract: A plug released into an oil or gas well carries one or more metallic strips that affect the inductance of a resistive-inductive bridge circuit mounted adjacent a conduit through which the plug and fluids are pumped into the well. This unbalances the bridge circuit to produce a signal preferably uniquely identified with the plug so that an indicator can be activated to confirm proper release of the plug into the well. When an amorphous metal is used in the metallic strips, the unbalancing of the bridge produces a signal having an identifiable harmonic of a fundamental frequency of an oscillator signal driving the bridge circuit, which harmonic is not present in other signals resulting from the bridge circuit being unbalanced by other materials flowing in the conduit.

Abstract: Casing slip joints are provided on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. In another aspect of the invention, the fracture initiation location is provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. Those slots are formed by a hydraulic jet which is directed through the opening and then pivoted generally about the point of the opening. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells.

Abstract: A seal for long-time exposures in oil and gas well tools. The seal is adapted for use in a sealed joint between two relatively movable members. In particular, the seal is designed for relatively slidable members. The seal has a body portion with a pair of annular arms extending from opposite sides thereof. A lip on each of the arms is adapted for engaging one of the relatively movable members. An elastomeric sealing element may be disposed in a groove in the body portion for dynamic sealing between the first and second members. Pusher rings may be disposed on opposite sides of the seal so that the seal may be clamped against one of the relatively movable members without the lips or arms longitudinally engaging either of the relatively movable members or a lock ring used to clamp the seal in place.

Abstract: A differential pressure actuating system for downhole tools provides endless operation by the use of the differential pressure between two isolated zones of a well as a power source for the tool. That differential pressure is applied across a power transfer element to operate the downhole tool.

Abstract: A swivel cementing head with manifold assembly. The assembly comprises a body connectable to a tool string, and a cementing manifold connectable to the cement source. The manifold is rotatably mounted on the body to provide continuous fluid communication between the manifold and body even when the body is rotating with respect to the manifold. The rotatable connection is provided by a mandrel extending from the body and the sleeve connected to the manifold. The mandrel defines a mandrel central opening therethrough and a transverse mandrel hole in communication with the mandrel opening, and the sleeve defines a transverse sleeve hole therethrough. The mandrel has a mandrel groove and an outwardly facing surface thereof adjacent to the mandrel hole, and the sleeve has a sleeve groove in an inwardly facing surface thereof adjacent to the sleeve hole.

Abstract: An electric coupling for two electric circuits in a well includes an electric contact and a contact receiver connected to respective ones of the circuits so that a contact/receiver pair is formed when the contact and receiver are moved together The receiver is sealed by a sealing member. The sealing member is disposed so that it is penetrated by the contact when the contact and receiver are moved together. A coupling including two such pairs is preferably used to connect two electric wires in the well to form a current conductive loop linking two electric coils. One of the coils is adapted to be moved in the well relative to the other coil which is adapted to be fixed in the well. In a preferred embodiment, one coil is on a wireline tool and the other coil is on a downhole tool.

Abstract: A fluid loss cell has an outlet through which fluid lost during a fluid loss test flows. This outlet is connected in closed pressure communication with a fluid measuring device that senses the amount of lost fluid received in the device and generates an electrical signal representative of the sensed amount. The signal is preferably provided to a computer so that automatic monitoring of the fluid loss occurs. The fluid measuring device contains blow off pressure and subsequent increased fluid amounts. Valves and pressure regulators are included in a preferred embodiment. A related method is disclosed.

Abstract: An apparatus for retrieving downhole devices is disclosed. The apparatus of the present invention includes a retrieving device that can be run on non-conventional workstrings such as coiled tubing, wireline, or electric line. The apparatus comprises a power mandrel, an inner sleeve mandrel slidably disposed within the power mandrel, and an overshot means. Means are provided to translate longitudinal movement of the power mandrel into rotational movement of the inner mandrel.

Abstract: A pressure transducer comprises a quartz crystal having an orientation within a range of angles between about -25.degree. and about -45.degree. relative to the Z axis of X, Y and Z crystallographic axes. Such a pressure transducer provides a useful pressure response at pressures and temperatures above those of the operating ranges of pressure transducers using AT-cut or BT-cut quartz crystals.

Abstract: A downhole formation test pump includes a progressive cavity pump having a helical rotor received in a helical cavity of a stator. The pump may be disengaged by withdrawing the rotor from the stator to provide a bypass position so that the downhole formation being tested can be allowed to flow freely if it is capable.

Abstract: A tube jetting apparatus for cleaning the interior surfaces of tubes such as those in heat exchangers. The jetting apparatus includes a hydraulically actuated lance and piston assembly in a housing. High pressure fluid is directed through ports in the lance and also directed across the piston to actuate the lance and piston assembly while providing high pressure fluid to a jetting nozzle on the lance. The speed of the lance and piston assmbly is controlled and jetting action occurs on both the outward and return strokes. On the return stroke, a pressure relief system is provided to relieve the system pressure through a differential pressure relief valve. A stroke limiter is provided which utilizes a collet for grippingly engaging the lance at a predetermined location thereon while minimizing damage to the surface of the lance.

Abstract: A rheological test apparatus and method using a helical screw rheometer. The screw in the rheometer is driven by a hydraulic motor controlled by a proportioning valve. A pressure transducer provides a pressure signal at the outlet of the rheometer, and a solenoid valve is used to close the outlet downstream from the pressure transducer. In a test, fluid is flowed into the rheometer. With the screw stopped and the discharge closed, a static pressure is measured by the pressure transducer, and a computer means resets this to a zero reference value. The screw in the rheometer is then rotated at a constant speed with the discharge closed, and the dynamic pressure at the outlet is measured by the pressure transducer. Because the static pressure was zeroed, the dynamic pressure value is substantially equal to the differential pressure across the rheometer. The test is repeated for different speeds.

Abstract: An annulus pressure responsive downhole tool includes a housing with a power piston slidably disposed therein. First and second pressure conducting passages communicate a well annulus exterior of the housing with first and second sides of the power piston. A flow restrictor is disposed in the second pressure conducting passage so that a relatively rapid increase in well annulus pressure creates a pressure differential across the power piston to move the power piston. A volume of silicone oil is contained in a first portion of the second pressure conducting passage between the second side of the power piston and the flow restriction, for accommodating displacement of the power piston as it moves. An operating element is disposed in the housing and movable from an initial position to a final position. The operating element is associated with the power piston so that the power piston moves the operating element from its initial position to an intermediate position.

Abstract: An apparatus and method of anchoring into a packer with a stinger assembly is disclosed. Further, an apparatus and method of releasing from a packer is also disclosed. The apparatus includes an elongated stinger member, a plurality of collet finger members slidably attached to the stinger, a shear ring member with a chamfered shoulder containing a plurality of splined extensions, with a plurality of shear pins contained through the shear ring member. Further, the apparatus includes a load ring attached to the elongated stinger for transferring the load of the downhole tool from the collet finger members to the load ring.

Abstract: An apparatus injects sealing balls into a well in response to closed loop control. The apparatus measures the fluid flow into the well, computes a total amount of fluid which has been introduced into the well, and actuates the release of a sealing ball upon a predetermined amount of fluid being reached. A related method is also disclosed.

Abstract: An apparatus and method utilize a neutron sensitive medium in which initially existing atoms of the medium are divided into particles, reaction energy and neutron energy. The medium undergoes polarization in response to the reaction energy and the neutron energy. This produces an electrical charge gradient which is proportional to the energies and which can be sensed and analyzed to indicate just the neutron energy.

Abstract: A power supply for providing electricity to one or more electrical circuits located downhole in a well comprises a fuel cell adapted to be disposed in the well with the electrical circuit(s). In addition to generating electricity, the fuel cell produces a byproduct liquid, such as water, which can be expelled from the power supply into the well despite substantial pressure, such as hydrostatic pressure, in the well. The fuel cell also generates heat which can be dissipated into the well through the wall of a housing of the power supply. The byproduct liquid can be circulated through the fuel cell to accomplish or assist in this heat dissipation.