801 results about "Measurement while drilling" patented technology

A transmitter antenna assembly for transient electromagnetic well logging instrument comprises an antenna coil coupled with a current source and a magnetic core having residual magnetization. Switching current in the antenna coil results in magnetization reversal in the magnetic core and change in magnetic dipole moment of the antenna. After the magnetization reversal is complete the current is removed and the new vector of magnetic dipole of the antenna maintains constant (steady-state phase of the antenna dipole) due to magnetic hysteresis of magnetic material employed for the magnetic core. No power expenditure during the steady-state phase of the magnetic dipole facilitates highly effective generation and fast switching of a large magnetic dipole. The magnetic core also serves as a shield between the antenna coil and any conductive part of the antenna assembly. Embodiments suitable for measurement-while-drilling or measurements through casing make use of residual magnetization of magnetic drill collar or magnetic casing respectively.

Methods and apparatus for making directional measurements of earth formations surrounding a borehole. New antenna coil shield designs are utilized to provide selective attenuation of at least one electromagnetic energy field component as the component interacts with the shield. The new shields are implemented in several downhole tool configurations to provide azimuthally focused formation measurements. In effect, the new shield filters interacting electromagnetic energy field components to pass those components corresponding to a magnetic dipole oriented at an angle from the tool axis. The shields thereby alter a coil's envelope of influence to electromagnetic energy. The new shields also form part of a system for making directional measurements while drilling.

A system and method for enhancing the reception of electromagnetic (EM) waves in a fixed downhole receiver of an EM telemetry system is provided. In one embodiment, slots are formed in a portion of an outer casing and an EM receiver is positioned within the outer casing so as to be aligned with the slots formed therein. In another embodiment, an inductive coupling arrangement is provided to transfer signals from an EM receiver mounted on the outside surface of an outer casing to a wireline that is attached to the outer surface of an inner casing, which is disposed within the outer casing. In yet another embodiment, an insulated gap is formed in the surface of the outer casing. An EM receiver, mounted on the outer surface of the inner casing, is positioned above the insulated gap of the outer casing. An electrical coupling mechanism is further provided to electrically couple the inner and outer conductors at a point above the EM receiver.

An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance.

An improved servo-driven pulser is disclosed, for use in measurement while drilling applications. In the pulser, a battery powered on-board DC electric motor is used to operate a servo-valve, which in turn adjusts internal tool fluid pressures to cause operation of a main valve to substantially reduce mud flow to a drill bit, thereby creating a positive pressure pulse detectable at the surface. De-energizing the motor driving the pilot valve results in re-adjustment of internal fluid pressures, causing the main valve to reopen, thereby terminating the pressure pulse.

A wellbore tool for locating a target wellbore containing a conductive member from a second wellbore and directing the trajectory of the second wellbore relative to the target wellbore includes an electric current driver having an insulated gap; a three-axis magnetometer positioned within a non-magnetic housing that is disposed within a non-magnetic tubular, the three-axis magnetometer positioned below the electric current driver; a drill bit positioned below the three-axis magnetometer; a hollow tubular connected between the electric current driver and the three-axis magnetometer; and a measurement-while-drilling tool. The current driver generates an electric current across the gap to the portion of the tool below the insulated gap. In a method a current is generated across the insulated gap to the portion of the tool below the insulated gap to the conductive material in the target wellbore returning to a portion of the bottom hole assembly above the insulated gap thereby producing a target magnetic field. Measuring the target magnetic field at the bottom hole assembly and the earth's magnetic field; and determining the position of the second wellbore relative to the target wellbore. Then steering the bottom hole assembly to drill the second wellbore along a trajectory relative to the target wellbore.

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. A preferred embodiment and three alternate embodiments of the modulator are disclosed.

A method for communicating data in an offshore data communication system comprises measuring L/MWD data with a sensor disposed in a bottomhole assembly positioned in a subsea borehole. The bottomhole assembly is disposed along a drillstring extending through the subsea borehole. In addition, the method comprises communicating the L/MWD data from the bottomhole assembly to the seafloor with a telemetry signal. Further, the method comprises receiving the telemetry signal with at least one telemetry transducer positioned proximal the sea floor. Still further, the method comprises processing the telemetry signal at the seafloor to produce a processed signal. Moreover, the method comprises transmitting the processed signal from the sea floor to the sea surface.

A well fluid sampling tool is provided. The sampling tool includes at least one insulated sample chamber mounted in a tool collar. The tool collar may be coupled with a drill string such that, when the tool collar is deployed in a well bore, selected sample chambers may receive a fluid sample from outside the drill string without removing the drill string from the well bore (e.g., during measurement while drilling or logging while drilling operations). A heating module in thermal communication with at least one of the sample chambers is disposed to selectively heat the sample chambers in thermal communication therewith. The sampling tool may be particularly useful for acquiring and preserving substantially pristine formation fluid samples.

The invention provides a short distance transmission system for wireless electromagnetic wave signals of a downhole near bit and a short distance transmission method, and belongs to the field of geosteering systems and measurement while drilling instruments in industries such as petroleum, mines and geological prospecting. The automatic gain control technology is adopted in the short distance transmission system for realizing the automatic adjustment of enlargement factors of downhole weak signals. The short distance transmission system comprises a short section receiving assembly and a short section transmitting assembly, wherein the short section receiving assembly and the short section transmitting assembly are respectively provided with a receiving antenna and a transmitting antenna. Due to the fact that radial coupled antennas are adopted, the short distance transmission system is relatively simple in structure. Meanwhile, the short distance transmission system is high in arithmetic speed and can meet demands for real-time transmission of a large number of signals. Moreover, a front end processing module special for the downhole weak signals is utilized for carrying out the automatic gain adjustment to the collected signals, maintaining stable output of the signals and lowering processing difficulty of subsequent signals, and therefore the signal transmission quality is greatly improved.

A method and apparatus used to transmit information to the surface from a subsurface location during the process of drilling a bore hole is described. A novel pressure pulse generator or “pulser” is coupled to a sensor package, a controller and a battery power source all of which reside inside a short section of drill pipe close to the bit at the bottom of the bore hole being drilled. The assembled apparatus or “MWD Tool” can be commanded from the surface to make a measurement of desired parameters and transmit this information to the surface by encoding data in pressure pulses generated by a pulser valve that includes a stator and a rotor which may be open and closed to create pressure pulses.

An earth model is formed in real time during drilling of a well by incorporating up-to-the-minute knowledge derived from geology, seismic, drilling, and engineering data. The process of forming the model utilizes Logging-While-Drilling (LWD) or Measuring-While-Drilling (MWD) data directly from the drilling rig as the well is drilled. The LWD or MWD data is sent to visualization centers and compared with other data such as existing geological models, the proposed well plan and present interpretation of the subsurface stratigraphy. The results of the comparison enable experts to analyze anomalous results and update the geological model within minutes of penetration of a formation during drilling. Well drilling efficiency is improved, and an “on-the-spot” road map is provided for maximal reservoir contact and pinpoint accuracy.

An assembly and methods for constructing a MONOWELL includes a monodiameter casing disposed in a monodiameter wellbore having diametric efficiency with a monobore production delivery system disposed within the monodiameter casing. An assembly for constructing a monodiameter wellbore includes a bottomhole assembly having a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool; a work string attached to the bottomhole assembly and extending to the surface; drilling fluids flowing through the work string and bottomhole assembly; chemical casing casing the borehole; expandable casing disposed in the wellbore; and a sealing composition disposed between the expandable casing and the wellbore.

A rotating, transversely magnetized, magnet on a drill collar induces magnetization in a casing of a preexisting well. A coil rotating synchronously with the magnet produces a current at twice the frequency of rotation and having an amplitude that depends upon the distance from the magnet to the preexisting well. Alternatively, a variable magnetic field is produced in the casing using a switchable magnet. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

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. Measurements are made while the circulation is terminated or while the well packers are being used to isolate an area of the wellbore from the circulating fluid. The method is used to directly measure and evaluate conditions caused by pumping and drill string movement, such as swab and surge pressures. Other conditions such as the formation strength, formation pressure, the fluid density, and other subsurface conditions related to the well are also measured.

The invention discloses a horizontal directional drilling guiding position method and position indicator, which comprises the following parts: sensing emission probe in the guiding drilling tool, walking type position follower and driller monitor on the drill, wherein the sensing emission probe is composed of angle sensor, signal disposing and transmitting unit, solenoid coil and battery, which sends the measured the incidence, facing angle, temperature and other parameters to the follower through wireless electromagnetic wave; the position follower calls the parameter of underground probe to measure position and depth according to the signal relative strength distribution, whose final result is sent to the driller display through wireless pattern. The invention is convenient to operate for the driller personnel.

A system for transmitting information in a well comprises a tubular string disposed in the well and having a drilling fluid flowing therethrough. A pulser is disposed in the tubular string and transmits a pulse synchronization marker comprising a chirp signal. A surface controller, acting under programmed instructions, detects the chirp signal adjusts a signal decoding technique based on the detected chirp signal.

The invention is direction and position drill-following survey apparatus comprising a drill collar, two V slots, metal shielding layer, tow gamma sensor, three-axis acceleration sensor, signal processing circuit module, high pressure sealing cover board, boring liquor conducting channel, upper slip ring connector, lower slip ring connector, wire hole. The invention integrated gamma survey and directional survey in just a short section which enables the drill not only survey the rock properties real-timely, but also tell the upper and lower rock characteristics when boring well., so to effectively find out the upper cover layer of the storage layer and seize the best timing entering the oil storage layer. Moreover, meanwhile assorting the upper and lower rock properties, the direction and drill status also can be obtained without any delay, which, facilitating adjusting the well boring track according to the geographic data and manage the drill travels a best track underground among the oil storage. The invention is suitable for geological guiding in fossil engineering.

An apparatus, system, and method for transmitting measurements while drilling are adapted for use with a drill string equipped with a mud motor. The drill string may comprise a plurality of interconnected drill pipe joints or a plurality of interconnected casing joints. The apparatus comprises a measurement-while-drilling tool adapted for placement in the drill string beneath the mud motor. The measurement-while-drilling tool has a system for transmitting telemetry signals, such as mud-pulse telemetry signals, upwardly through the mud motor and the drill string. In particular embodiments, the measurement-while-drilling tool has a system for transmitting mud-pulse telemetry signals upwardly through the mud motor and the drill string at frequencies below approximately 1 Hz, although other frequencies may be employed to advantage. The apparatus may further comprise a rotary steerable system for placement in the drill string beneath the mud motor. The rotary steerable system may be a point-the-bit system or a push-the-bit system. In particular embodiments, the rotary steerable system and the measurement-while-drilling tool are integrated.

The invention relates to a device in an electromagnetic measurement while drilling system for receiving an electromagnetic signal with measurement data information sent underground on the ground and transmitting the signal to a data processing computer, and a method thereof. The device uses two antennas in a well field to receive an electromagnetic signal sent underground and a well field noise signal respectively; and the two signals enter a program controlled low noise preamplifier to be amplified through the coupling of an impedance converter, then enter a signal conditioning module for processing, and then enter a digital signal processing module through analog-to-digital conversion, and finally data is transmitted to a computer terminal through an interface module. The device is matched with a downhole electromagnetic signal transmitter to form the electromagnetic measurement while drilling system to form the information communication between underground and ground. The electromagnetic measurement while drilling system is not affected by drilling fluid medium, can perform data transmission without circulating a drilling fluid under any working condition, and can solve the measurement while drilling problem in gas drilling and aerated drilling.