Abstract: A drilling mud clarification or reclamation system is provided. High gravity and low gravity solids are removed from the drilling mud in respective centrifugal separator stages. A plurality of in-line mass flow sensors are provided to provide real-time indication of the effectiveness of the clarification of the drilling mud, and to provide control signals to a central control station. The heavier weight components are separated from the mud and returned to the system for further use. The lighter weight components are removed and are discarded to clean the mud. A cuttings dryer is provided to remove oil from cuttings which have been separated from a shale shaker stage. A de-sludging centrifuge is also provided to remove very fine cuttings which may have a harmful effect on the viscosity of the mud.

Abstract: A method of drilling a well having a first tubular member extending from the surface of the well to a position proximate the bottom of the well. The first tubular member has an inner annulus therethrough. A fluid is pumped into the well through the inner annulus of the first tubular member to flush drilling cuttings out of the well. A fluid is also injected into the well, exterior to the inner annulus, to control the bottom hole circulating pressure in the well.

Abstract: A borehole includes a tubular member, a sealing member for sealing an annulus between the tubular member and the borehole, a pump for pumping fluidic materials into the tubular member, and an automatic choke for controllably releasing pressurized fluidic materials out of the annulus. A system and method monitor the operating pressure within the tubular member and compare the actual operating pressure with a desired operating pressure. The difference between the actual and desired operating pressure is then processed to control the operation of the automatic choke to thereby controllably bleed pressurized fluidic materials out of the annulus thereby creating back pressure within the borehole.

Abstract: A closed-loop circulating system for drilling wells has control of the flow rates in and out of the wellbore. Kicks and fluid losses are quickly controlled by adjusting the backpressure. Kick tolerance and tripping margins are eliminated by real-time determination of pore and fracture pressure. The system can incorporate a rotating BOP and can be used with underbalanced drilling.

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. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system modifies the rate of boring tool displacement along the underground path while rotating the boring tool at a selected rotation rate to optimize excavation productivity. The controller may also monitor the rate at which liquid is pumped through the borehole and automatically adjust 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.

Abstract: A pulser providing pressure based accoustic telemetry in a fluid column includes a formed turbine and valve wheel moveable as one unit, an aft turbine configured to drive the valve wheel and a brake to inhibit movement of the aft turbine. During periods when the aft turbine is slowed relative to the formed turbine and valve wheel, the aft turbine blocks misalign with blades of the valve wheel inhibiting fluid flow therepast. A pressure buildup is caused hereby until the brake is released allowing the aft turbine blades to realign with the valve wheel by resuming speed rotation thereby terminating pressure buildup.

Abstract: An oscillating shear valve system for generating pressure fluctuations in a flowing drilling fluid comprising a stationary stator and an oscillating rotor, both with axial flow passages. The rotor oscillates in close proximity to the stator, at least partially blocking the flow through the stator and generating oscillating pressure pulses. The rotor passes through two zero speed positions during each cycle, facilitating rapid changes in signal phase, frequency, and/or amplitude facilitating enhanced, multivalent data encoding. The rotor is driven by a motorized gear drive. In one embodiment, a torsional spring is attached to the motor and the resulting spring mass system is designed to be near resonance at the desired pulse frequency. The system enables the use of multivalent encoding schemes for increasing data rates.

Abstract: Methods and systems are provided for drilling a well bore 60 through a subterranean formation using a drilling rig 25 and a drill string 50, whereby the bottom hole pressure while circulating drilling fluid (“ECD”) may be substantially maintained when circulation is interrupted or altered, such as when adding a joint of drill pipe to or removing a joint of drill pipe from the drill string. The method includes controllably applying and maintaining a desired variable annulus fluid pressure in the well bore, and thereafter controllably releasing the pressure from the well bore 60. In addition, methods and systems are provided for rotating the drill string while trapping, maintaining and/or releasing the well bore pressure. A substantially constant ECD pressure may be maintained on a formation, thereby facilitating the use of a lower density drilling fluid than may otherwise be required to maintain well control.

Abstract: The present invention provides continuous or near continuous motion drill strings which include motion sensitive and other MWD sensors which take stationary measurements while the drilling assembly is continuing to drill the wellbore. For simultaneous continuous drilling and stationary measurements, the present invention provides a drilling assembly wherein a force application system almost-continuously applies force on the drill bit while maintaining a housing or drill collar section stationary. Motion sensitive sensors carried by the drill collar take stationary measurements. A steering device between the drill bit and the force application system maintains drilling of the wellbore along a prescribed well path.

Abstract: A system for controlling the operating pressures within a subterranean borehole. The borehole includes a tubular member, a sealing member for sealing an annulus between the tubular member and the borehole, a pump for pumping fluidic materials into the tubular member, and an automatic choke for controllably releasing pressurized fluidic materials out of the annulus. The system monitors the operating pressure within the tubular member and compares the actual operating pressure with a desired operating pressure. The difference between the actual and desired operating pressure is then processed to control the operation of the automatic choke to thereby controllably bleed pressurized fluidic materials out of the annulus thereby creating back pressure within the borehole.

Abstract: A down-hole tool comprises a generally tubular body for connection in a drill string, the body typically having an upper tubular member and a lower tubular member interconnected to be axially secured and relatively rotatable, and a frangible element securing the upper and lower members together rotationally and adapted to rupture at a predetermined load

Abstract: A minimum volume apparatus and method is provided including a tool for obtaining at least one parameter of interest of a subterranean formation in-situ, the tool comprising a carrier member, a selectively extendable member mounted on the carrier for isolating a portion of annulus, a port exposable to formation fluid in the isolated annulus space, a piston integrally disposed within the extendable member for urging the fluid into the port, and a sensor operatively associated with the port for detecting at least one parameter of interest of the fluid.

Abstract: Methods and systems are provided for maintaining fluid pressure control of a well bore 30 drilled through a subterranean formation using a drilling rig 25 and a drill string 50, whereby a kick may be circulated out of the well bore and/or a kill fluid may be circulated into the well bore, at a kill rate that may be varied. A programmable controller 100 may be included to control execution of a circulation/kill procedure whereby a mud pump 90 and/or a well bore choke 70 may be regulated by the controller. One or more sensors may be interconnected with the controller to sense well bore pressure conditions and/or pumping conditions. Statistical process control techniques may also be employed to enhance process control by the controller. The controller 100 may further execute routine determinations of circulating kill pressures at selected kill rates.

Abstract: A pressure pulse generator for use in transmitting pressure signals to surface in a fluid-based drilling system. The generator is arranged in use in the path of a pressurized fluid to operate a drilling assembly and is capable of being actuated to generate pressure signals in such fluid for transmission to surface pressure monitoring equipment. The pulse generator includes pulse height compensation to keep the pulse height within acceptable limits over a wide flow range.

Abstract: A method for controlling a subsea well that includes shutting at least one blowout preventer, opening at least one isolation line, and circulating an influx out of a well while an inlet pressure of a subsea mudlift pump is adjusted to maintain a substantially constant drill pipe pressure at an initial circulating pressure. After the influx is circulated out of the well, drilling mud with a kill mud weight is pumped into the well. The drill pipe pressure is reduced according to a preselected drill pipe pressure decline schedule until the kill mud weight drilling mud reaches the bottom of the well. The drill pipe pressure is then maintained at a final circulating pressure by adjusting the inlet pressure of the subsea mudlift pump. The kill mud weight drilling mud is then circulated from the well bottom to the surface at the final circulating pressure.

Abstract: A novel method, system and tool for performing formation and well evaluation while drilling are disclosed. These inventions determine the properties of a particular formation within a reservoir as the reservoir is being intersected during well construction. In one form of the invention, the formation evaluation is made using a direct measurement of the formation's ability to flow fluids. The flow potential of a reservoir during underbalanced well construction is determined as the well is being constructed. The methods produce an understanding of the volumes and types of fluids such as oil, gas, and/or water, that can be produced out of discrete sections of a formation within a reservoir as the reservoir is intersected.

Abstract: A closed-loop drilling system and method of drilling oil, gas, or geothermal wells is described, whereby through the control of the flow rates in and out of the wellbore, and by adjusting the pressure inside the wellbore by a pressure/flow control device installed on the return line, surface pressure being increased or decreased as required, this in turn decreasing or increasing downhole pressure, occurrence of kicks and fluid losses may be greatly minimized and quickly controlled. Through the method of the invention the elimination of the kick tolerance and tripping margin on the design of the well is made possible, since the pore and fracture pressure will be determined in real-time while drilling the well, and, therefore, nearly no safety margin is necessary when designing the well, reducing significantly the number of casing strings necessary.

Abstract: Subsurface wellbore conditions are measured directly in the wellbore while the fluid circulation system is not pumping. The measured values are recorded at the subsurface location and subsequently transmitted to the well surface when circulation is resumed using fluid pulse telemetry (FPT). Real-time measurements made when the fluids are circulating are transmitted real time using FPT. Axially spaced measurements are used to obtain differential values. The apparatus of the invention comprises an assembly carried by a drill string that is used to selectively isolate the area within the well that is to be evaluated. The apparatus includes an assembly having axially spaced inflatable well packers that are used to isolate an uncased section of the wellbore. The apparatus is equipped with self-contained measuring and recording equipment, a fluid receiving reservoir, circulation valving, measurement while drilling equipment, and automated controls.

Abstract: The present invention provides a tool and method for obtaining at least one parameter of interest such as pressure of a subterranean formation in-situ. The tool comprises a carrier member for conveying the tool into a borehole, at least one selectively extendable member mounted on the carrier member for separating the annulus into a first portion and a second portion, a first port exposable to formation fluid in the first portion, a second port exposable to a fluid containing drilling fluid in the second portion, a first sensor for determining a first value indicative of a first portion characteristic, a second sensor for determining a second value indicative of a second portion characteristic referenced to the first value.

Abstract: A method and apparatus facilitating the event-synchronized recording of data at different locations, such as may occur at and within a borehole during a Measurement-While-Drilling (“MWD”) operations. In a seismic survey the method and apparatus uses three subsystems: 1) a seismic source; 2) a borehole receiver, and 3) a pinger. When used in a borehole containing a drill string, the pinger strikes or vibrates the drill string causing an acoustic signal to traverse the drill string. The signal reaches a borehole receiver where it is detected. The signal is also reflected back up the drill steering to a sensor, nominally an accelerometer sensor, associated with a pinger where it is time-stamped by inclusive timing circuitry.

Abstract: An apparatus is used with a drilling assembly for drilling a borehole. The drilling assembly has an impact device linked to a drill head. The impact device is powered by a first fluid under a first pressure to impart a percussive force to the drill head. The percussive force is a function of the first pressure. A thruster of the drilling assembly is also linked to the drill head. The thruster is powered by a second fluid under a second pressure to impart a thrust force to the drill head. The thrust force is a function of the second pressure. Additionally, a rotator of the drilling assembly is linked to the drill head. The rotator is powered by a third fluid under a third pressure to impart a torque to the drill head. The torque is a function of the third pressure. The apparatus includes a first pressure sensor communicating with the first fluid to output a first electrical signal that is a function of the first pressure.

Abstract: A method for a dynamic shut-in of a subsea mudlift drilling system. The method comprises detecting a kick, isolating a wellbore, and adjusting a subsea mudlift pump and a surface mud pump to provide a selected wellbore pressure. Selected well parameters are measured and used to calculate a kick intensity.

Abstract: A method for a dynamic shut-in of a subsea mudlift drilling system. The method comprises detecting a kick, isolating a wellbore, and adjusting a subsea mudlift pump and a surface mud pump to provide a selected wellbore pressure. Selected well parameters are measured and used to calculate a kick intensity. The invention is also a method for a dynamic shut-in of a subsea mudlift drilling system including detecting a kick and isolating a wellbore. A first inlet pressure of a subsea mudlift pump and a first drill pipe pressure are measured. A rate of the subsea mudlift pump and a rate of a surface mud pump are adjusted to pre-kick circulation rates. A second inlet pressure of the subsea mudlift pump and a second drill pipe pressure are recorded. The measured values are used to calculate a kick intensity.

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. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system modifies the rate of boring tool displacement along the underground path while rotating the boring tool at a selected rotation rate to optimize excavation productivity. The controller may also monitor the rate at which liquid is pumped through the borehole and automatically adjust 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.

Abstract: A mud separator monitoring system utilizing electronic transducers positioned in various locations in the mud separator and the lines leading from the mud separator to the mud return pit and gas discharge flare for obtaining data during drilling operations to calculate the volume of gas retained in the drilling fluid, the hydrostatic head of the drilling fluid and gas pressure in the separator on a continuing basis and informing field personnel of conditions in the mud separator indicating potential hazard. The system further monitors continuously the volume of injected gases and hydrocarbon gases circulated during drilling operations for making adjustments to the volume of injected gases required to sustain the drilling operations.

Abstract: Methods and systems are provided for drilling a well bore 60 through a subterranean formation using a drilling rig 25 and a drill string 50, whereby the bottom hole pressure while circulating drilling fluid (“ECD”) may be substantially maintained when circulation is interrupted or altered, such as when adding a joint of drill pipe to or removing a joint of drill pipe from the drill string. The method includes controllably applying and maintaining a desired variable annulus fluid pressure in the well bore, and thereafter controllably releasing the pressure from the well bore 60. In addition, methods and systems are provided for rotating the drill string while trapping, maintaining and/or releasing the well bore pressure. A substantially constant ECD pressure may be maintained on a formation, thereby facilitating the use of a lower density drilling fluid than may otherwise be required to maintain well control.

Abstract: An apparatus for improved detection of underground well kicks, preferably comprising a first acoustic sensor mounted on the top drive of a drilling rig in acoustic contact with a liquid level within a drill string which is generally located within a wellbore, a second acoustic sensor in a trip tank connected to the wellbore, and a drawworks position indicator. The acoustic sensors detect signals reflected from liquid level interfaces allowing calculation of injected liquid volumes from the trip tank into the wellbore and liquid volume changes within the drill string. The drawworks sensor allows calculation of tubular volumes removed from the wellbore over time. Comparison or totaling of calculated volumes allows early detection of unwanted fluid fluxes between the wellbore and an underground formation.

Abstract: A drilling fluid analyzing apparatus has at least two sensors is used to analyze drilling fluid that contains cuttings. The sensors are mounted vertically spaced in a well riser and in communication with well return fluid. The sensors convert the pressure exerted by the return fluid to signals that are then conveyed to a processor. The processor determines the density of the return fluid, and the fluid density is indicative of borehole cleaning efficiency. Two additional sensors may be added to the drilling fluid input mud pipe to sense the pressure exerted by the drilling mud before it is contaminated with cuttings.

Abstract: Systems and methods for controlling an underground boring tool involve rotating the boring tool and sensing a parameter of boring tool rotation. The boring tool is also displaced along an underground path and a parameter of boring tool displacement is sensed. Various sensors monitor boring machine activities, boring tool location, orientation, and environmental condition, and geophysical and/or geologic condition of the soil/rock at the excavation site. Data acquired by these sensors is processed by a boring machine controller to provide closed-loop, real-time control of a boring operation. The controller receives the boring tool signal and other sensor signals in real-time and, in response, transmits control signals to each of the rotation and displacement units substantially in real-time so as to control one or both of a rate and a direction of boring tool movement along the underground path.

Abstract: An early formation evaluation tool is provided which includes formation fluid sampling capabilities. In one embodiment, fluid pressure in a drill string in which the tool is interconnected is utilized to operate packers of the tool and to operate fluid samplers of the tool. To successively control actuation of the samplers, a ratchet mechanism responsive to altering fluid pressures in the drill string aligns a piercing member with a series of frangible pressure barriers associated with the samplers.

Abstract: An iterative drilling simulation method and system for enhanced economic decision making includes obtaining characteristics of a rock column in a formation to be drilled, specifying characteristics of at least one drilling rig system; and iteratively simulating the drilling of a well bore in the formation. The method and system further produce an economic evaluation factor for each iteration of drilling simulation. Each iteration of drilling simulation is a function of the rock column and the characteristics of the at least one drilling rig system according to a prescribed drilling simulation model.

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. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system modifies the rate of boring tool displacement along the underground path while rotating the boring tool at a selected rotation rate to optimize excavation productivity. The controller may also monitor the rate at which liquid is pumped through the borehole and automatically adjust 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.

Abstract: Systems and methods for controlling an underground boring tool involve rotating the boring tool and sensing a parameter of boring tool rotation. The boring tool is also displaced along an underground path and a parameter of boring tool displacement is sensed. Various sensors monitor boring machine activities, boring tool location, orientation, and environmental condition, and geophysical and/or geologic condition of the soil/rock at the excavation site. Data acquired by these sensors is processed by a boring machine controller to provide closed-loop, real-time control of a boring operation. The controller receives the boring tool signal and other sensor signals in real-time and, in response, transmits control signals to each of the rotation and displacement units substantially in real-time so as to control one or both of a rate and a direction of boring tool movement along the underground path.

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: An apparatus and method is provided for substantially continuously drilling and disposing of drill cuttings and dust to minimize airborne contamination while providing protection against overload. A drill stem with a bit is advanced by a drill head to form the drill hole. A flushing mechanism utilizes vacuum or pressurized water for flushing the cuttings and dust from the drill hole for disposal. A transducer monitors at least one parameter of the fluid flow. A controller is utilized to regulate the rate of drilling dependent on the signal level of the parameter being monitored.

Abstract: The present invention provides a fluid flow measurement system for an oil well drilling system that includes a supply of drilling fluid to a wellbore under pressure and a return line carrying fluid leaving the wellbore during drilling of the wellbore. The system includes at least one floating sensor in the return line that provides a measure of the velocity of the fluid in the return line. The sensor may be a thermal sensor, an electromagnetic sensor or an ultrasonic sensor. A height sensor provides the fluid level in the return line and a density sensor provides the density of the returning fluid. A controller determines the inflow rate and out flow rate of the drilling fluid and further determines the presence of a kick and wash out from the flow rates. The system also determines the operating condition of the pumps supplying fluid to the wellbore.

Abstract: A method of drilling a bore hole is described. A desiccant is added to a Hydrocarbon Based Fluid (Crude Oil—Refined Oil—Diesel Fuel—Mineral Oil—etc.) used as a drilling fluid to drill bore holes (Oil and Gas Wells—Mine Shafts—etc.) to react with any water (H2O) present to generate a water free fluid. Several advantages result from accomplishing the water removal process including higher drilling rates, lower fluid preparation and maintenance costs, lower drilling fluid pumping costs, improved solids removal from the drilling fluid at the surface, improved bore hole conditions and improved environmental cleanup of the drill solids waste.

Abstract: An apparatus for erecting a foundation element in a ground surface including a drilling device, a pumping device, a pressure transducer and a control unit. The drilling device includes a hollow core tube and an auger bit adapted to drill a hole in the ground surface while the pumping device is adapted to pump a solidifying suspension material under pressure through the hollow core tube and into the hole in the ground surface. In addition, the pressure transducer is mounted on the core tube and is adapted to provide a pressure signal indicative of a pressure of the solidifying suspension material in the core tube while the control unit is adapted to control the pressure of the solidifying suspension material.

Abstract: Integrated drilling and evaluation systems and methods for drilling, logging and testing wells are provided. The drilling and evaluation systems are basically comprised of a drill string, a drill bit carried on a lower end of the drill string for drilling a well bore, logging while drilling means included in the drill string for identifying subsurface zones or formations of interest, packer means carried on the drill string above the drill bit for sealing a zone or formation of interest below the packer means, and a fluid testing means included in the drill string for controlling the flow of well fluid from the zone or formation of interest into the drill string. The drilling and evaluation systems and methods for using the systems allow one or more subsurface zones or formations of interest in a well to be drilled, logged and tested without the necessity of removing the drill string from the well.

Abstract: A system is disclosed for generating and transmitting data signals to the surface of the earth while drilling a borehole, the system operating by generating pressure pulses in the drilling fluid filling the drill string. The system is designed to maximize signal strength while minimizing the probability of jamming by drilling fluid particulates. The system uses a rotary valve modulator consisting of a stator with flow orifices through which drilling fluid flows, and a rotor which rotates with respect to the stator thereby opening and restricting flow through the orifices and thereby generating pressure pulses. The flow orifices with the stator in a “closed” position are configured to reduce jamming, and to simultaneously minimize flow area in order to maximize signal strength. This is accomplished by imparting a shear to the fluid flow through the modulator, and minimizing the aspect ratio and maximizing the minimum principal dimension of the closed flow area.

Abstract: An apparatus and method is provided for substantially continuously drilling and disposing of drill cuttings and dust to minimize airborne contamination while providing protection against overload. A drill stem with a bit is advanced by a drill head to form the drill hole. A flushing mechanism utilizes vacuum or pressurized water for flushing the cuttings and dust from the drill hole for disposal. A transducer monitors the negative or positive gauge pressure. A controller is utilized to regulate the rate of drilling dependent on the signal level of the pressure being monitored. In the preferred embodiment utilizing air, the passage in the drill stem removes the cuttings/dust and is connected to a transfer duct, which in turn is connected to a filter and the intake side of a blower. The controller is programmable to establish the optimum rate of feed of the drill head. The rotary motion of the drill bit can also be regulated by the controller.

Abstract: The present invention provides a method for improving the quality of a formation fluid sample by taking the sample at a time when the formation fluid composition contains the most favorable portion of hydrocarbons. This task is accomplished by determining in real-time, the composition of the fluid flowing into a downhole tool from the formation. This method determines the optical density of the fluid as the fluid flows through the tool. An optical spectrum is generated from the density measurement. The optical spectrum is compared to a composite spectrum generated from a database of known fluid samples. As a result of the comparisons, there is a determination of the derivations between corresponding features of the two spectra. Adjustments are made to the components of the composite spectrum until the deviations between the two spectra are at an acceptable minimum. Determinations of the fluid composition are made from the composition of the composite spectrum at the minimum deviation.

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 and apparatus for communicating with a device downhole in a well, such as a bottom hole assembly in a drill string. Pressure pulses, such as those generated by the pistons of the mud pump, are transmitted through the drilling mud to a pressure pulsation sensor in the bottom hole assembly. The pressure pulsation sensor features a piezoceramic element that generates a varying voltage signal in response to the received pressure pulsations. The pressure pulsation sensor also has electronic components that allow it to analyze a characteristic of the pressure pulsations, such as their frequency. Based on its analysis of the pressure pulsations, the sensor can decipher a command from the surface, for example, that directs the steering of a steerable drill string, or that can determine whether the mud pumps are operating.

Abstract: A mud separator monitoring system utilizing electronic transducers positioned in various locations in the mud separator and the lines leading from the mud separator to the mud return pit and gas discharge flare for obtaining data during drilling operations to calculate the volume of gas retained in the drilling fluid, the hydrostatic head of the drilling fluid and gas pressure in the separator on a continuing basis and informing field personnel of conditions in the mud separator indicating potential hazard. The system further monitors continuously the volume of injected gases and hydrocarbon gases circulated during drilling operations for making adjustments to the volume of injected gases required to sustain the drilling operations.

Abstract: A mud pulse telemetry system uses a downhole pulser to produce sequences of positive and/or negative pulses according to a selected pattern. Positive pulses, negative pulses, and combinations thereof may be produced. A flow rate sensor at the surface measures changes in the flow rate at the top of the wellbore instead of or in addition to changes in the pressure. The flow rate changes are detectable even though the pressure pulses themselves may have a poor signal to noise ratio. This enables the invention to function effectively in underbalanced drilling wherein the use of light muds with a high gas content is required. One embodiment of the invention uses a conventional downhole pulser with the main valve closed and the pilot valve operating in a direct pulse mode.

Abstract: Calcium oxide (C.sub.a O--Hot Lime--Processed Lime) is added to a Hydrocarbon Based Fluid (Crude Oil--Refined Oil--Diesel Fuel--Mineral Oil--etc.) used as a drilling fluid to drill bore holes (Oil and Gas Wells--Mine Shafts--etc.) to react with any water (H.sub.2 O) present to generate a water free fluid. Several advantages result from accomplishing the water removal process including higher drilling rates, lower fluid preparation and maintenance costs, lower drilling fluid pumping costs, improved solids removal from the drilling fluid at the surface, improved bore hole conditions and improved environmental cleanup of the drill solids waste.

Abstract: A method is presented for accurately surveying and determining the profile of the path of a subterranean wellbore containing a constant density fluid extending contiguously throughout. A first pressure sensor, associated with a downhole tool, is traversed station-by-station along the wellbore for measuring the pressure of the fluid within the wellbore at each station. A second pressure sensor is located within the wellbore fluid at a known elevation. The elevation of the first pressure sensor, at a station, is determined by adding the calculated differential height to the known absolute elevation of the second sensor. As each elevation is referenced to the second sensor, no cumulative errors are incurred. If the density of the fluid is unknown, a third pressure sensor within the wellbore fluid can be provided at a known elevation different from that of the second sensor. The areal position of each station is determined by conventional means associated with the downhole tool.

Abstract: A procedure is described for determining the power output of a downhole drilling motor, when the motor is inside the wellbore. The technique uses stand-pipe pressure and fluid flow rate as the main inputs. The power output of the motor is calculated by carrying out two low flow stall tests at flow rates lower than the drilling flow rate. These tests result in "off-bottom" and stall pressures at the two flow rates. Another off-bottom pressure is taken at the actual flow rate that will be used during drilling operations. From the use of the off-bottom and stall pressure measurements, a determination is made of the differential pressure across the motor and the stall pressure at the actual drilling fluid flow rate. A full power curve and a predicted operating stand-pipe pressure for optimal power generation are provided based on an experimentally verified assumption regarding the change in rotation rate of the motor versus the differential pressure across the motor power section.

Abstract: A well drilling system for drilling with gaseous drilling fluid, particularly natural gas, in a closed circulation path including an enclosure or bell nipple mounted on a wellhead between the wellbore and a rotary control head for the drillstem. The enclosure redirects the flow of cuttings laden gaseous drilling fluid being circulated out of the well and includes a plurality of fire extinguishing fluid injection nozzles arranged to inhibit or extinguish fire within the enclosure and the rotary control head. Drill cuttings are separated from the gaseous drilling fluid in a pressure vessel which includes separator baffles and a drill cuttings port and valve arrangement for dumping samples and substantial quantities of drill cuttings collected within the pressure vessel during operation of the system. The enclosure and fire extinguishing system may be used in conjunction with operations using conventional liquid drilling fluids and conventional liquid-solids separation equipment.