Abstract: A well testing method and apparatus for reservoir characterization during a drilling operation by making use of conventional drilling facilities. The tests can be performed at various degrees of wellbore penetration in the formation. If the test is conducted as soon as the top of the formation is penetrated by the bit, the effects of formation damage (skin) may be minimized or even eliminated. The proposed technique is particularly suitable for formations displaying weak pore structure, tight formation, and/or relatively low reservoir pressure. The method consists of two major steps; a drawdown test with a variable rate, and a build up test. A computer simulator is necessary and also useful for pressure transient analysis for determination of reservoir pressure and transmissibility. From the data recorded from a single well test utilizing this method and apparatus, fluid mobility and formation thickness can be calculated.

Abstract: Hydraulic drilling method and apparatus in which the drilling fluid itself is utilized to control the direction in which a hole is bored in the earth. The orientation of the drill head is monitored by tilt and roll sensors, and the discharge of drilling fluid through radially or obliquely directed nozzles is controlled by poppet valves in accordance with the orientation to control the direction in which the hole is cut.

Abstract: A multi-conduit tubular having fluid conduits (30) and electrical conduits (108), with associated surface fluid (182) and electrical (186) commutators, and downhole sensors (18, 20, 290) for providing surface monitors (22) with instantaneous formation data. Each tubular (50) includes a plurality of uniform linear conduits (30) therethrough, with a gasketed seal plate (86) interposed between joined tubulars for assuring a high pressure seal between joined conduits. The seal plate (86) includes an intermediate electrical connector (126) for connecting electrical conduit connectors (116) of one tubular to another. A coupling collar (84) with uniform diameter internal coarse and fine threads (92, 94) joins the tubular ends having similar threads by differential thread action without respective tubular rotation.

Abstract: A transducer assembly includes a piezoelectric transducer and a support member encasing the transducer. The transducer and the support member may have commonly disposed openings. The support member has a progressively increasing thickness at progressive positions from the opening to distribute equally the stresses at the different positions on the piezoelectric transducer. A plurality of such transducer assemblies may be disposed at spaced positions in an oil well with the support members supported on a support rail extending through the well. The support rail serves as an electrical ground. A bus bar extends through the well at positions corresponding substantially to the centers of the transducer assemblies. The bus bar is supported by electrically insulating spacer members extending from the support rail. A ring is supported at one end by the support rail and is coupled at the other end to a tubing. The tubing envelopes, the transducer assemblies, the support rail, the bus bar and the spacer members.

Abstract: A pneumatic pressure regulating system controls a choke having a hydraulic operator actuator for selectively opening or closing the choke to control pressure in a well casing. The system applies periodic pulses of pneumatic pressure for opening an output valve in one direction when the actual casing pressure is greater than a selected control pressure for opening the choke, and applies periodic pulses of pneumatic pressure for opening the output valve in another direction when casing pressure is less than the set pressure for closing the choke. The interval between sucessive pulses is adjusted to be long enough for the pressure in the casing to equilibrate before the next pulse occurs.

Abstract: A method for circulating and maintaining a drilling mud in a wellbore drilled into a subterranean formation at a desired pressure during drilling operations, said method consisting essentially of;(a) circulating drilling mud through a drill pipe in the wellbore into the wellbore, maintaining a desired pressure in said wellbore and recovering drilling mud from the wellbore at a controlled rate using a mud pump and mud pit arrangement; and,(b) maintaining a second supply of drilling mud in fluid communication with the drill pipe at a suitable pressure so that when the mud pump fails to maintain pressure in the drill pipe, drilling mud is supplied from the second supply of drilling mud to maintain pressure in the wellbore.

Abstract: A pneumatic system is used for controlling the position of a hydraulically-actuated drilling choke to limit the maximum pressure in the casing of an oil well. Pressure in the casing is used directly to switch a converter valve that applies air pressure to the pressure limiting system. The air pressure opens the choke to relieve casing pressure. The system traps a volume of air at a pressure corresponding to the choke position and uses this pressure as a memory signal for resetting the choke to its preset position after casing pressure has decreased below its allowable maximum. The system also uses pneumatic pressure to assure that the memory is not lost before the choke is reset.

Abstract: An apparatus which comprises an upper sub for connectable engagement with the wire line, a microprocessor component for directing the various functions of the overall apparatus down hole; a motor section having a plurality of thrust directional motors and ball screw assembly for movement of steering gates; a motor driven impellar means for providing thrust and flow through a portion of the apparatus and in combination with the flow gates providing steering in a certain direction; an electric transducer portion for providing ultrasonic vibrations around the circumference of the apparatus in discongealing molecular substrate adjacent the apparatus; a mechanical vibration coil assembly means on the lower end of the apparatus for discongealing larger areas of congealing in a substrate around the apparatus, and a lower sub for connectably engaging the electrical logging unit to be steered down hole.

Abstract: Hydrojet drilling means and method are presented. The method varies the angle and direction from which fluid contacts the material to be cut. The variation in angle and direction also causes the fluid to be applied to selected points and then repeatedly reapplied from different angles and directions getting the advantages of pulsed hydrojet cutting. As a result, 10,000 psi fluid streams cut as well in certain strata as prior art 50,000 psi hydrojets. The means comprises a recyclable fluid supply, means to clean the fluid stream, stringer means which may comprises as little as a cable with the associated fluid flow and power flow lines, a down hole pressure intensification means, and a drill head disposed about an axis formed by the stringer having at least three orifices disposed at equal angles about the axis. In operation, the drill head both rotates and is swung in a complex three dimensional selected series of pendulum-like arcs as the drill head is lowered.

Abstract: A control and recorder system for a blowout preventer for providing a record of operation and status of the various components of the blowout control system at periodic times and after a function operation. The system monitors various functions such as whether the accumulator pump is running, the open and close status of the various rams, bypass, annular, flow line, kill line and choke line as well as various pressures, such as in the annular, the accumulator and the manifold, flow measurements of various fluids in the system and provides alarms for various parameter values. Control and status information may be transmitted through fiber optic cables between various control stations at the rig floor, accumulators and remote locations for avoiding interference by electrical noises or radio frequencies and providing a safety link through hazardous gas areas.

Abstract: Method and apparatus are described to reduce the tension required on a riser pipe used in offshore drilling between a floating vessel and a subsea wellhead. Heavy drilling fluid is circulated down a drill pipe and up the annulus between the drill pipe and the borehole wall to a point just above a subsea wellhead. From this point, a separate drilling fluid return conduit extends to the floating vessel. Means are provided to maintain a constant level of an interface between the heavy returning drilling fluid and the lightweight fluid which can be confined within the riser pipe.

Abstract: A gas bubble is circulated from a well by a system that maintains the well and bottom hole pressure substantially constant by progressively increasing the casing pressure as needed to maintain the drill pipe pressure substantially constant. An incrementally increasing casing pressure reference signal is produced by detecting each occurrence of the drill pipe pressure falling a predetermined amount below a drill pipe pressure reference signal. The casing pressure reference signal is compared with the actual casing pressure. A throttling valve is closed a corresponding amount if the acutal casing pressure is less than the casing pressure reference signal. The throttling valve is opened a corresponding amount if the actual casing pressure is greater than the casing pressure reference signal.

Abstract: A system and method are disclosed which eliminates the use of a riser pipe in underwater drilling operations. The system includes a mud sump connectable to the top of a submerged wellhead and has a bottom with a mud inlet provided therein and an upwardly extending wall cooperating with the bottom to support a quantity of mud, the sump restricting the water to contact with only the upper surface of the mud as the mud passes upwardly through the mud inlet in the bottom. A hose, separate from the drill string, is used to carry mud to the surface of the water. A pumping means is used to pump mud through the hose in response to the quantity of mud supported within the sump to thereby return the mud to the surface of the water without the use of a riser pipe.

Abstract: A normally open shutdown system for a high pressure gas well is disclosed which comprises a pressure-operated motor valve, a pressure sensor, and a pressure regulator, all on a conduit installed in the high pressure line leading from the gas well.

Abstract: An improved offshore drilling method and apparatus are disclosed which are useful in preventing formation fracture caused by excessive hydrostatic pressure in a drilling riser. Gas is injected into the riser to provide the lift necessary to return the drilling fluid to the surface and to reduce the density of the drilling fluid. The rate of gas injection overlifts the drilling fluid to the extent that the pressure of the fluid is reduced to less than that of the seawater surrounding the riser. Seawater is permitted to flow into the lower end of the riser in response to the differential pressure between the drilling fluid and seawater so that the pressures of the drilling fluid and the seawater approximately equalize.

Abstract: An improved offshore drilling method and apparatus are disclosed which are particularly useful in preventing formation fracture caused by excessive hydrostatic pressure of the drilling fluid in a drilling riser. One or more flow lines are used to withdraw drilling fluid from the upper portion of the riser pipe. Gas injected into the flow lines substantially reduces the density of the drilling fluid and provides the lift necessary to return the drilling fluid to the surface. The rate of gas injection and drilling fluid withdrawal can be controlled to maintain the hydrostatic pressure of the drilling fluid remaining in the riser and wellbore below the fracture pressure of the formation.

Abstract: An improved method and apparatus used for offshore drilling operations is disclosed which is particularly useful in those operations where a floating vessel or drilling platform is situated at the surface of a body of water with a riser assembly extending between the platform and the well and a blowout preventer assembly is positioned therebetween near the lower end of the riser assembly. In the practice of this invention at least one fluid bypass conduit provides a path for high pressure fluid to flow from the wall at a point below at least one of the blowout preventers to the riser assembly at a point below the surface of the water and above the blowout preventer assembly. A means in each of said bypass conduits controls the flow of fluid through the conduit to regulate the fluid pressure in the well when the blowout preventers are in the closed position.

Abstract: There is disclosed a device and a method for controlling the flow of fluid from a well bore. The device comprises a fluid control valve placed in the choke line of a well and has a shaped helical or spiral duct formed in one embodiment by a tapered screw-like plug engaging a hollow sleeve. In another embodiment, the plug is cylindrical and screw-like threads are formed in the hollow sleeve. The valve increases the degree of control over well bore pressure and flow rate as the well bore pressure fluctuates. The valve responds automatically to changes in the well bore pressure and is controlled by a control system including a hydraulic circuit and controls which visually indicate the position of the screw-like plug with respect to the hollow sleeve. The movement of the plug is controlled by the control system and the net pressure exerted on the plug by the fluid flowing through the control valve from the well bore.

Abstract: The present invention relates to a method of preventing drilling fluid overflow and uncontrolled formation fluid blowouts when removing drill pipe sections from a drill string disposed in a well bore which penetrates a subterranean formation and is filled with drilling fluid. A gas is introduced into the annulus until a predetermined gas pressure is reached therewithin thereby displacing drilling fluid from the well bore and downwardly in the annulus a distance such that upon releasing the gas pressure from the annulus the level of drilling fluid in the drill string is below the level at which the drill pipe sections are disconnected therefrom, but above the level at which the hydrostatic head exerted on the formation by the drilling fluid equals the pressure of fluids contained within the formation.