Abstract: An apparatus and method for controlling an underground boring machine during boring or reaming operations. A boring tool is displaced along an underground path while being rotated at a selected rate of rotation. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system concurrently modifies the rate of boring tool displacement along the underground path while rotating the boring tool at the selected rotation rate. The controller monitors the rate at which liquid is pumped through the borehole and automatically adjusts the rate of displacement and/or the liquid flow rate so that sufficient liquid is flowing through the borehole to remove the cuttings and debris generated by the boring tool. Sensors are provided to sense pressure levels in the rotation, displacement, and liquid dispensing pumps and an electronic controller continuously monitors the levels detected by the sensors.

Abstract: The air flow rate through a rock drill bit is measured while the drill bit is connected to a drill string. A tube of a manometer is inserted into a channel of the drill bit while an air flow is conducted through the drill string and channel, whereby the manometer measures a pressure of the air flow in the channel. From that measurement, a nominal air flow rate is calculated. The nominal air flow rate is corrected as a function of at least one parameter selected from: a difference between a temperature of air entering the drill bit and a temperature of air ambient to the drill bit, and a height of the drill bit above sea level.

Abstract: A system for separation of fluids and drill cuttings received from a borehole during an under-balanced drilling procedure. The system is designed to cope with significantly varied pressures and flow rates, particularly in relation to gas content of drill fluids returned to the surface during the drilling process in a production zone, and to provide effective separation and to reduce the detrimental effect due to the presence of the drill cuttings in the returned drill fluids. In the present invention there is utilized a first stage, high pressure vessel in which a major portion of the gases ad drill cuttings are separated, and a second stage, horizontal low pressure vessel, preferably of greater volume than the high pressure vessel, in which further separating is achieved, including the separate removal of the drilling liquid to be returned to the drill tube.

Abstract: A system for separation of fluids and drill cuttings received-from a borehole during an under-balanced drilling procedure. The system is designed to cope with significantly varied pressures and flow rates, particularly in relation to gas content of drill fluids returned to the surface during the drilling process in a production zones and to provide effective separation and to reduce the detrimental effect due to the presence of the drill cuttings in the returned drill fluids. In the present invention there is utilized a first stage, high pressure vessel in which a major portion of the gases ad drill cuttings are separated, and a second stages horizontal low pressure vessel, preferably of greater volume than the high pressure vessel, in which further separating is achieved, including the separate removal of the drilling liquid to be returned to the drill tube.

Abstract: In a drill string pressure pulses are generated by expansion and constriction of an elastic body to transmit information along the drill string.

Abstract: A pressure pulse generator, or "pulser," and methods for operation are described. The pulser is constructed of a stator and rotor mounted within a housing, each being configured with a central hub and one or more radially extending lobes. An equal number of ports are spaced between the lobes. The lobes of the rotor are cross-sectionally tapered in the streamwise direction. The rotor and stator are maintained within the housing in a coaxial spaced relation from each other. The axial distance between the rotor and stator may be selectively varied by a linear actuator. In a preferred embodiment, the linear actuator comprises a conventional solenoid assembly which is operably associated with the rotor to move it axially within the housing with respect to the stator between a first position, wherein the distance between the rotor and stator is reduced, and a second position, wherein the distance between the rotor and stator is increased. The linear actuator is energized in response to signals from an encoder.

Abstract: The drilling fluid returns from underbalanced drilling are introduced into a separator and a separate gas stream is recovered. The gas stream is cleaned at the well site to remove entrained liquid and particulate solids, to produce gas suitable to be fed to a compressor. The cleaned gas is compressed to re-injection pressure and recycled to the well.

Abstract: A method and apparatus is disclosed to identify fluid hydrocarbon flow rates in a flow line such as a pipeline or a producing oil well having a unidirectional fluid flow including moving an acoustic tool through a flow line. Acoustic energy is transmitted into the fluid flow. The acoustic energy is then received when it is reflected back by interfaces within the fluid flow. The reflected acoustic energy is transformed into electrical signals. The electrical signals are rectified. The amplitude peaks of the rectified electrical signals are determined. The travel times of the amplitude peaks are also determined. The amplitude peaks and the time values are used to determine hydrocarbon gas and the hydrocarbon liquid in the hydrocarbon fluid flow in the oil well. A transducer within the acoustic tool rotates three hundred sixty degrees six times per second. This enables us to obtain holdup and velocities for the total flow around the tool even in non ideal operating conditions such as deviated wells.

Abstract: A method and apparatus for determining the various components of a multi-phase fluid flow in a defined area includes using an acoustic transceiver tool to direct a beam of acoustic energy toward the fluid flow in a producing well or a horizontal line. A signal is generated when the reflection of the beam of acoustic energy returns and is detected. The signal is rectified and recorded as a measure of oil flow rate within the well. The amplitude peaks are identified and areas around each peak are determined. Two areas of the rectified signal are defined relating to the determined amplitude peaks. The rectified signal under each area is integrated to provide an indication of fluid flow and the strength of the signal reaching the casing. A ratio is determined from the integration results of the two areas. The magnitude of this ratio provides an indication of the extent of the presence of gas in the fluid flow.

Abstract: An apparatus and method for controlling an underground boring machine during boring or reaming operations. A boring tool is displaced along an underground path while being rotated at a selected rate of rotation. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system concurrently modifies the rate of boring tool displacement along the underground path while rotating the boring tool at the selected rotation rate. The controller monitors the rate at which liquid is pumped through the borehole and automatically adjusts the rate of displacement and/or the liquid flow rate so that sufficient liquid is flowing through the borehole to remove the cuttings and debris generated by the boring tool. Sensors are provided to sense pressure levels in the rotation, displacement, and liquid dispensing pumps and an electronic controller continuously monitors the levels detected by the sensors.

Abstract: A method for detecting changes in the rate of discharge of fluid from a well bore. Firstly, providing a flow nipple having a first end, a second end, and a flow line connection extending substantially radially from the flow nipple intermediate the first end and the second end. Secondly, providing a drilling fluid treatment tank. Thirdly, providing a flow line having a first end and a second end. The first end is connected to the flow line connection of the flow nipple and the second end to the drilling fluid treatment tank. This creates a flow path for drilling fluids from the flow nipple along the flow line to the drilling fluid treatment tank. Fourthly, providing an elongate antechamber adjoining one of the flow nipple, the flow line or the drilling fluid treatment tank. The elongate antechamber has a first end and a second end. The first end is positioned in fluid communication with the flow path.

Abstract: An improved formation testing method increases the accuracy of in-situ formation pressure measurements by characterizing the mudcake properties. Specifically, after a formation tester is lowered to a desired depth within a wellbore, a pad is extended to gently abut and seal against the mudcake without disturbing the mudcake. When pressed against the mudcake, the pad experiences momentarily higher pressures, which are measured by a probe housed by the pad. These pressures may be enhanced by briefly rejecting fluids through the probe, so as to avoid disturbing the mudcake. The probe continues to measure pressure, which eventually decreases relative to hydrostatic pressure in the wellbore, due to the flow of high-pressure wellbore fluids through the mudcake.

Abstract: A self-propelled turbo siren modulator assembly is disclosed for use in an MWD system. The turbo siren includes a fixed turbine deflector located upstream from a rotor, which in turn is located upstream from a fixed stator. Drilling mud flowing through the turbine deflector causes the rotor to rotate independent of any external drive device. The rotor and stator preferably have a similar configuration, which includes at least one lobe and at least one port so that the rotor alternatively blocks or permits mud flow through the port(s) of the stator to create a cyclical acoustic wave signal, with a frequency that depends upon the number of lobes on the rotor and the velocity of the drilling mud. Encoded measurement data is modulated on the carrier frequency wave through the use of amplitude modulation, frequency modulation or phase shift modulation, or a combination thereof to maximize data rates.

Abstract: A method and apparatus for communicating coded messages in a wellbore between a transmission node and a reception node is provided. The coded messages are messages are impressed upon a fluid column which extends between the transmission node and the reception node. A transmission apparatus is provided at the transmission node which is in communication with the fluid column, for altering pressure of the fluid column to generate at least a portion of the coded message. A reception apparatus is provided at the reception node. The reception apparatus includes a rigid structural component with an exterior surface which is in direct contact with fluid column and an interior surface which is not in contact with the fluid column, and a sensor assembly which detects elastic deformation of the rigid structural component. The transmission apparatus is utilized to alter pressure of the fluid column in a predetermined pattern to generate at least one coded message.

Abstract: The present invention is a differential pressure fluid density production logging tool. The tool comprises an elongated housing adapted to traverse a wellbore. The housing has ports in hydraulic communication with the wellbore at spaced apart locations. The tool also comprises a differential pressure transducer having two inputs, a selective valve, and a reference tube filled with a liquid having a known density. The valve is selectively operable to shunt the inputs of the transducer, to connect the reference tube across the inputs of the transducer to calibrate the transducer, and to connect the ports across the inputs of the transducer to enable measurement of the fluids in the wellbore.

Abstract: A method of reducing fluid loss into a highly conductive formation interval during drilling and completion of a well through such an interval wherein a foamed cement slurry, including an acid or oil soluble component, is injected into the well and forced into the conductive portions of the formation zone, which may comprise a fractured or rubblized formation portion. The cement is allowed to harden or set at a porosity of at least 15%, followed by resuming drilling and, in completing the well, dissolving the soluble component to increase the permeability of or disintegrate the cement to permit production of formation fluids into the well.

Abstract: An acoustic detector in a mud pulse telemetry system includes a bypass loop in parallel with a section of the main mud line that supplies drilling mud to a drill string. The detector includes a pair of pressure sensing ports in the bypass line, and one or more pressure transducers for detecting the pressure at different locations in the bypass loop so that the differential pressure can be measured. The bypass loop has a small internal passageway relative to the main mud supply line and may include a constriction so as to create two regions in the passageway that differ in cross sectional areas. Forming the pressure sensing ports in the regions of differing cross sectional areas allows the pressure transducers to more precisely detect the mud pulse signals. Because of its relatively small cross sectional area, only a small fraction of the drilling mud flows through the bypass loop. The bypass loop may thus be constructed of hydraulic hose and a relatively small rigid body having a central through bore.

Abstract: A method of warning of the onset of pipe sticking in a rotary drilling operation using a drill string comprising: (a) monitoring the pressure of a drilling fluid being pumped through the drill string during drilling over predetermined periods of time to obtain series of pressure measurements; (b) monitoring the torque required to rotate the drill string during said periods to obtain series of torque measurements; (c) obtaining the skew (third moment) of each series of pressure measurements according to the relationship ##EQU1## wherein N is the number of pressure measurements xi in the series, xmean is the average value of the measurements in the series, and .sigma. is the standard deviation of the measurements in the series; (d) obtaining the normalized standard deviation .sigma.n of the torque measurements in each corresponding series of torque measurements according to the relationship .sigma.n=(.sigma./ymean) wherein .sigma.

Abstract: A method and apparatus for measuring fluid flow rates, reservoir deliverability and/or the absolute open flow (AOF) potential of a subterranean formation penetrated by a wellbore. The present invention can be described as a formation fluid flow rate test tool which is conveyed and operated on a wireline logging cable. The down hole test tool comprises an arrangement of inflatable packers to isolate an interval and a pump which extracts fluid from the formation through an inlet below the upper most packer. The method allows for sequentially increasing or decreasing the flow rates and measuring the corresponding pressure responses. From this data, the reservoir flow characteristics, properties and deliverability can be accurately calculated, which was not previously permitted with other known wireline conveyed sampling and testing tools. Additionally, the present invention allows for the reservoir parameters to be obtained under dynamic conditions, emulating a deliverability test.

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: A sidewall contact parameter tool, adapted to be disposed in a mud-filled wellbore, includes a pad assembly, in accordance with the present invention, which is adapted to cut through mudcake and measure a parameter of a formation disposed under the mudcake. The wellbore wall includes a mudcake and an earth formation disposed under the mudcake. The pad assembly includes at least one formation parameter sensor, and the formation parameter sensor includes a base portion and a knife edge portion integrally connected to the base portion. The base portion of each formation parameter sensor is adapted to contact a surface of the mudcake but the knife edge portion is adapted to cut into the mudcake and contact or penetrate a surface of the earth formation disposed under the mudcake. The knife edge portion of each sensor includes an internal space or pinhole aperture, and a parameter sensing apparatus disposed within the internal space or aperture.

Abstract: Rotational orientation of a drillstring is monitored a plurality of times during each rotation of a drillstring for monitoring the rotational orientation of a curve drilling assembly on a drillstring. A defined rotational orientation of a downhole location on the drillstring with respect to the curve drilling assembly is established. At least one reference signal generator having a known relationship to the down hole location on the drillstring and that rotates with the drillstring is provided at the surface. A reference signal is generated each time a reference signal generator rotates past a detector. A pressure signal is generated each time the drillstring rotates through the defined rotational orientation with respect to the drill bit steering device. Occurrences of the plurality of surface reference signals and the pressure signal are timed and compared for monitoring the rotational orientation of the drill bit steering device.

Abstract: A method of maintaining a constant predetermined hydrostatic pressure in a wellbore being drilled by a rotary drilling process utilizing aerated drilling fluid. The aerating gas, such as compressed air, is maintained at a constant pressure while its flow is changed in response to changes in the flow of the drilling fluid. This maintains a constant ratio of compressed air to drilling fluid, resulting in the hydrostatic pressure remaining constant.

Abstract: Fluid influx in a borehole is determined by examining and monitoring the computed transfer function in the signal channel defined by the annulus between the borehole and a drillstring in the borehole.

Abstract: A rotating pulse valve for use in a mud pulse telemetry system is presented. In accordance with the invention, a valve is diametrically mounted in a channel of a segment of a drill string wherein drilling fluids flows. The valve comprises blades which are configured so as to be impelled (i.e., rotated) by the flow of the drilling fluid. An escapement mechanism is employed to restrain the valve in selected positions thereby at least partially obstructing the flow of the drilling fluid which results in generating positive pressure pulses or waves in the drilling fluid in response to downhole conditions.

Abstract: Sensing apparatus for monitoring fluid intake and discharge pressure in an oil well comprises an intake pressure transducer mounted at the bottom of an ESP pump string and arranged to sense intake pressure directly and a similarly mounted discharge pressure transducer. A capillary tube is connected at its lower end to the transducer and indirectly at its upper end to a fluid reservoir located in the area of discharge pressure. Valves in the form of alternative nipples are arranged to apply intake or discharge pressure to the fluid reservoir through a port in the wall of the by-pass string. While discharge pressure is normally monitored via the capillary tube, the intake pressure can be monitored in the event of breakdown of the discharge pressure transducer, thus providing redundancy to the system; also the ability to sense intake pressure at two different points enables the system to be calibrated.

Abstract: In one broad aspect, the invention provides a method of receiving instructions for an implement, for example, a drill string stabilizer, mounted on a drill string, which instructions are transmitted by varying the rate of flow of, or pressure exerted by, the fluid in the bore of the drill string in accordance with one of a plurality of predetermined sequences; the method comprising the steps of:a) monitoring variations in the rate of flow of, or pressure exerted by, the fluid in the drill string;b) comparing the sequence of monitored variations with a plurality of predetermined sequences, each predetermined sequence corresponding to a set of instructions for the implement; andc) eitheri) ignoring the variations if they do not correspond to a predetermined sequence, orii) if the variations do correspond to a predetermined sequence, executing the instructions which correspond to that sequence.

Abstract: A method is provided for detecting outflow of fluid from an offshore wellbore to a surrounding earth formation or inflow of fluid from the formation of the wellbore. The wellbore is in fluid communication with a conduit extending between the wellbore and an offshore structure floating above the wellbore, which wellbore and conduit are at least partly filled with a body of fluid. Liquid is injected into the body of fluid at a first predetermined flowrate, and liquid is discharged from the body of fluid at a second predetermined flowrate. A variation of the content of the body of fluid is then determined.

Abstract: In accordance with the present invention, several methods are presented for the detection of gas into an offshore marine riser (e.g., riser gas). In a first embodiment of this invention, an acoustic transmitter is positioned on or nearby the subsea blowout preventor stack and imparts continuous low frequency waves into the annular fluid in the marine riser. These imparted waves define pressure perturbations which are received by a pressure transducer positioned on the riser at a location above the acoustic transmitter. Gas detection in the riser is then indicated by determining the rate of change of certain characteristics of the output. The output characteristics are preferably the moduli and phase angles of the acoustic fundamentals and their harmonics.

Abstract: Gas influx into a wellbore, called A "kick", is detected by two different, yet complementary methods during active drilling of the borehole. The first method is based upon the existence of standing wave patterns generated by pressure oscillations of the drilling rig mud pumps. Such standing wave patterns form time sequences of maximum and minima as a gas slug moves upwardly in the annulus. The time between such peaks of such oscillations is measured and forms the basis for generation of one first kick signal. A continuous increase in the phase between annulus and drill string standing waves forms the basis for another standing wave kick signal. The second method uses acoustic signals from a downhole source near the bottom of the borehole which are transmitted at different speeds in the annulus mud and in the interior drill string mud, where the annulus mud may be gas cut. A difference in arrival time between the signals is determined, and if large enough, causes a second kick signal to be generated.

Abstract: A method of determining the rotational orientation of a downhole tool on a rotatable conduit, such as a collar on a drillstring in a borehole, without interrupting the rotation of the drillstring, includes establishing the initial rotational orientation of the downhole tool; creating a pressure change to generate a signal; providing a reference point on the conduit; generating a reference signal each time the reference point rotates past a detector; generating the signal each time the conduit rotates through the defined rotational orientation with respect to the tool; and timing and comparing the occurrences of the referenced signal and the signal in order to monitor the rotational orientation of the downhole tool.

Abstract: A method of real time analysis and control of a fluid influx from an underground formation into a wellbore being drilled with a drill string, a drilling and circulating from the surface down to the bottomhole into the drill string and flowing back to the surface in the annulus defined between the wall of the wellbore and the drill string, the method comprising the steps of shutting-in the well, when the influx is detected; measuring the inlet pressure P.sub.i or outlet pressure P.sub.o of the drilling mud as a function of time at the surface; determining, from the increase of the mud pressure measurement, the time t.sub.c corresponding to the minimum gradient in the increase of the mud pressure and controlling the well from the time t.sub.c.

Abstract: The invention relates to a method of analyzing fluid influxes into an oil well from an underground formation. During a drilling mud transient flow state, the successive values of the rate Q.sub.i or pressure p.sub.r of injection of the drilling mud into the well and the successive values of the rate Q.sub.r or pressure p.sub.r of return of the drilling mud to the surface are measured. The changing values of the rate or pressure of injection are compared with the changing values of the return rate or pressure. From this comparison the nature and volume of the fluids that have penetrated into the well are determined.

Abstract: A method of and a device for remotely-controlling at least one piece of drill string equipment from an instruction issued from the surface. The method includes issuing from the surface a first information sequence to cause a first predetermined action according to a predetermined sequence, detection of a condition indicative of a second sequence resulting from the first sequence, comparison of this second sequence with another predetermined sequence, and operating the equipment only if there is similarity between the latter two sequences. The method can be applied to actuation of a variable-angle bent element.

Abstract: A whipstock mill for milling through the casing wall which incorporates a pressure drop tattletale to signal the operator that the milling operation should be halted. The milling tool includes a longitudinal fluid passageway which communicates with a lateral port formed below the mill blades. A replaceable plug is utilized to initially close the port thereby restricting fluid flow into the well hole. The starter mill is preferably run into the hole with a whipstock which can be set in the hole using an integral packer. As the mill travels down the set whipstock, a shear block mounted to the whipstock will shear the plug at a predetermined depth of the mill opening the lateral port. The resulting pressure drop within the milling tool signifies that the mill has reached the desired depth. Accordingly, the milling operation can be halted and the mill retrieved to permit further operations through the casing wall.

Abstract: In the preferred application, an acceleration compensation mass is supported in a downhole drilling related housing for independent movement along an axis in response to acceleration of the housing. A control member that moves relative to the housing in a direction parallel the axis to carry out the function of the housed apparatus is connected to a piston in a cooperating bore in the housing to displace fluid when the member moves. A second piston and cooperating bore in the housing is arranged to displace fluid when the mass moves. Fluid plumbing is arranged to connect the two hydraulic cylinders such that the mass and the member, if they move, must move in unison in opposite directions. When the housing is accelerated in the direction along the axis, both member and mass tend to move in the opposite direction relative to the housing but each piston opposes the other and no movement occurs if the pistons have effective areas proportional to the weights of the related member and mass.

Abstract: In a process of downhole drilling in an open hole, where the drill bit has struck a lost circulation zone in the wall of the formation, and mud circulating through the annulus during drilling has been lost into the zone and therefore circulation of the mud has been lost, the process for locating the depth of the lost return zone would include the steps of (a) detecting a drop in the mud level within the annulus of the drill casing to a central depth; (b) introducing a quantity of lighter fluid such as 8.

Abstract: Methods for the early detection of gas kicks in marine risers (10) include monitoring a downhole absolute pressure and a downhole differential pressure of a riser section (11) positioned just above the blowout preventer (18). The absolute pressure is used to calculate an average density of mud or mud/gas mixture in the entire riser (10). The differential pressure across the riser section (11) is used to calculate an average density of mud or mud/gas mixture in riser section (11). An unfavorable comparison between the calculated density for the mud or mud/gas mixture in the riser section (11) and the calculated density for the mud or mud/gas mixture in the entire riser (10) is used to detect the onset of a gas kick and to alert the operator. Alternatively, the measured differential pressure across the riser section (11) can be compared with an expected downhole differential pressure. Unfavorable comparisons of the measured and expected differential pressures indicate the onset of a gas kick.

Abstract: For a self-controlling drill rod for rotary boring rods of machine rock drills, comprising an inner drilling shaft adapted to be connected with the boring rods and the boring tool and having a flush channel and a housing mounted on the drilling shaft so as to be rotatable thereabout, control bars capable of swinging out being disposed on the outside of the housing, and the parts of the hydrostatic drives acting on the control bars as well as the control electronics and control electrical system being provided within the housing, whereby the required energy is generated by the rotary motion during the boring operation, the inventive improvement is that an annular space exists between the drilling shaft and the housing having a radial connection with the flush channel of the drilling shaft and being closed off at each end by a rotary check valve keeping out the borehole fluid, and that the annular space serves as a tank for the working fluid of the hydraulic system, said fluid being formed by the drilling shaft

Abstract: A flowing crosslinked polymer gel is employed as a lost circulation fluid in a process for reducing lost circulation during an oil field drilling operation. The lost circulation fluid comprises a carboxylate-containing polymer, a chromic carboxylate crosslinking agent, and an aqueous solvent.

Abstract: The flow rate of the drilling mud within a drill string is measured by measuring the doppler frequency shift in an acoustic signal propagated from a first acoustic transducer to a second acoustic transducer laterally separated from the first acoustic transducer. Each of the transducers are disposed within the principal flow of the drilling mud. The degree of doppler shift is a measure of the flow rate of the drilling mud between the two transducers. Variations in the flow rate of the drilling mud as measured by the transducers downhole are used to transmit information or commands from the well surface to a downhole microprocessor coupled to the output of the transducers.

Abstract: A nonflowing crosslinked polymer gel is employed in a lost circulation treatment for reducing lost circulation during an oil field drilling operation. The nonflowing gel comprises a carboxylate-containing polymer, a chromic carboxylate crosskinging agent, and an aqueous solvent.

Abstract: Apparatus and method for orienting a collar on a fluid conducting conduit, such as a drill string, includes an orifice through the wall of the conduit and a latch assembly for latching the collar to the conduit. The latch assembly allows fluid communication through the orifice and rotates the collar when the conduit is rotated in a first direction about the longitudinal axis of the conduit. The latch assembly unlatches the collar from the conduit, prevents fluid communication through the orifice, and allows the conduit to rotate relative to the collar when the conduit is rotated ion a second, opposite direction.

Abstract: A variety of flow and pressure measurements are obtained to characterize the drilling fluids hydraulics system of the borehole drilling process. Notably, a differential pressure measurement which measures the difference between the pressure internal to and external of the drill bit is made close to the drill bit. From this and other measurements are obtained valuable information on whether a change in pressure drop is due to a leak or a lost bit nozzle, on corrections to the downhole weight on bit measurement, on the rate of rotation of a downhole positive displacement drilling motor, on the efficiency of the drilling motor, and on an indication of whether a leak in or a blockage of the drill string has occurred and its location.

Abstract: A drill string deflection tool is arranged to function as a segment of drill string. An upper and a lower portion telescope together to form a mid-section with limited telescoping movement and limited angular deflection of the axes of the opposite ends. Axial load compresses the tool and a cam and fulcrum arrangement deflects the tool when it is axially compressed. The tool extends axially when pulled in tension and the axis becomes straight. Drilling fluid pressure acts on rams in the tool to lock it in whatever state exists when pressure is applied. The locking mechanism acts upon the drilling fluid channel to cause a pressure drop, detectable at the surface, that indicates the state of the tool downhole.

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 well logging system which monitors the flow rate of a fluid flowing in a borehole traversing an earth formation includes a sonde. A transmitter located in the sonde transmits acoustical waves into the fluid at a predetermined frequency. A receiver also located in the sonde receives reflected acoustical waves. The receiver also provides a signal corresponding to the received reflected acoustical waves. The provided signal is processed for being sent uphole by way of a cable. Electronics at the surface include circuitry which derives the velocity of the fluid in accordance with the frequency of the processed signal and the predetermined frequency. The circuitry provides an output signal corresponding to the derived velocity of the fluid flowing the borehole.

Abstract: A drilling fluid saver valve apparatus incorporating a pressure test device. The apparatus includes a tubular body having a valve seat and a closure check valve moveably mounted in spring loaded relation within the body to be normally seated in closed relation to permit flow of fluids under pressure only from a drilling kelly into the drillpipe, and a pressure test device connected into a side port formed in the body between the valve seat and drillpipe.

Abstract: The orientation of a downhole steering assembly used in drilling a horizontal well is located with respect to the earth using a sub placed above the downhole assembly. The sub comprises a housing having a central bore defining an inlet flow passageway said housing further defining a toroidal chamber in communication with said passageway. The toroidal chamber has a pocket, a valve seat, and a spherical valve that is rotatable in said toroidal chamber from a normally seated position in the pocket. Upon rotation of the drill string the spherical valve plugs the valve seat and causes an increase in the resistance to flow in the drilling mud through the drill string that can be detected at the surface.

Abstract: The invention relates to the control of rotary type oil drilling operations. During a drilling test in which the drill string is held against vertical motion at the surface, known as the "drill-off test", an exponential decrease as a function of time, in the weight applied to the drill bit (WOB) is noted as is a threshold where the value of WOB remains constant. From this test the drillability of the formation drilled, the bit wear and the actual value of the weight applied to the bit may be determined.