Abstract: Conventional drill pipe is rotated at a rate sufficient for distributing deforming forces substantially uniformly around the circumference of the drill pipe at each location along the length of the drill pipe disposed within the curved portion while the pipe is passed through the curved portion of a short-radius wellbore. The drill pipe arrives in the lateral portion in operable condition for drilling to extend the lateral portion and is retrieved from the wellbore in reusable condition.

Abstract: An electrical connector assembly 10 provides electrical connection between a surveying tool 53 positioned within a drillstring in a curved portion of a borehole and an electronics package 27 positioned in a vertical portion of the borehole. A non-conductive support 16 of the electrical connector assembly 10 is electrically connected to the surveying tool 53 and passes freely through a tool positioning pipe 18 and an adapter 14 for mounting the non-conductive support in the tool positioning pipe. A receptacle 24 for the non-conductive support 16 is electrically connected to the electronics package 27 for completing a plurality of electronic circuits between the surveying tool 53 and the electronics package when contacts 20 of the non-conductive support establish connection with contact elements 28 of the receptacle.

Abstract: A novel method for characterizing multilayer subterranean reservoirs comprising forming a single layer reservoir model representative of the flow parameters of the multilayer reservoir and developing a set of predicted flow rates from a numerical reservoir simulator. The predicted flow rates are scaled to form a set of dimensionless flow rates. Differences between actual reservoir flow rates and predicted flow rates obtained from the dimensionless flow rates, are minimized automatically to obtain estimates of flow parameters for each layer of the multilayer reservoir. Additionally, for a given set of flow parameters, the optimum injection and production well patterns as well as injection and production well operating conditions can be determined for producing hydrocarbon from the multilayer reservoir.

Abstract: A method of geophysical exploration is provided whereby satellite derived and surface acquired gravity data sets can be employed to produce a merged gravity data set. In particular, surface acquired gravity data can be filtered so as to have a frequency content matching the satellite acquired gravity data. Employing mistie analysis, both gravity data sets can be combined to produce a merged gravity data set. The resulting merged gravity data set provides means for referencing both non-overlapping surface acquired gravity data sets and satellite derived gravity data sets to a common or reference datum such that they can be compared directly.

Abstract: A method which combines fluid drive and gravity drainage to produce hydrocarbons from a subterranean formation comprises injecting a fluid through at least two upper horizontal wells out into the formation for moving hydrocarbons from the formation into at least one lower horizontal well through which the hydrocarbons are produced, wherein each lower horizontal well is spaced laterally and vertically below and between two respective upper horizontal wells; and producing hydrocarbons through the at least one lower horizontal well at a cumulative rate faster than the cumulative rate of the fluid injected into the upper horizontal wells. The method further comprises injecting a fluid and producing hydrocarbons as just described but with additional upper and lower horizontal wells longitudinally spaced from the first-mentioned upper and lower horizontal wells so that each of the lower horizontal wells operates as a discrete production well.

Abstract: A method is disclosed for obtaining an estimate of the shear velocity in a formation material. Utilizing compressional velocity (V.sub.p) and density (.rho.) of the formation material, formation aggregate mineral parameters and formation pore fluid parameters together with a relationship that the frame bulk modulus/frame shear modulus is approximately equal to the bulk modulus of the aggregate mineral grains/shear modulus of the aggregate mineral grains, to obtain an estimate of the shear wave velocity (V.sub.s) of the formation material. The present invention is primarily designed for use in the areas where shear wave velocity (V.sub.s) measurements are unobtainable due to unconsolidated formations, and specifically, wherein the acoustic velocity of formation fluids and/or wellbore fluids is greater than the desired shear wave velocity.

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 fault-tolerant method and system for processing global transactions in a distributed database system. If a fault occurs in the distributed database system, a transaction management system will suspend the processing of a transaction and renew it when the fault is remedied. The transaction management system identifies one or more sites in the distributed database system that contain data needed for a global transaction and divides each transaction into subtransactions for processing at one or more identified sites. If a fault occurs in the distributed database system, the transaction management system maintains the status of each subtransaction. When a fault in the distributed database system is corrected, the transaction management system updates the status of each subtransaction and restarts processing of the transactions.

Abstract: The present invention provides novel methods for identifying, characterizing and mapping seismic noise as an aid in evaluating and enhancing seismic data. In particular, an array of seismic receivers can be beam steered to sense seismic energy arriving from a plurality of azimuths. A measure of the strength of the seismic energy for each azimuth can be obtained for a plurality of arrival times, velocities and distances from the array. Displays of the azimuthal distribution of the strength of the seismic energy sensed by the areal array can then be produced for identifying and characterizing seismic noise into seismic data.

Abstract: The present invention provides an improved method of processing and displaying geophysical data so as to enhance the evaluation and interpretation of subtle variations in the earth's geological and lithological structures. In particular, the dynamic range of geophysical data is compressed to more nearly approximate the inherent dynamic range limitations of visual displays of the geophysical data.

Abstract: An improved method of stratigraphic analysis of geophysical data is provided. In one embodiment seismic data are transformed into one or more instantaneous attributes descriptive of the wave-like nature of the seismic signals comprising the seismic data. A stratum in the earth's subsurface, having both lateral and vertical extent, is defined on the seismic data. The instantaneous attributes within the stratum can thereafter be transformed into a descriptor statistically representative of changes in the formation materials comprising the stratum. The descriptor can then be plotted in both cross-sectional and plan view so as to identify and characterize both lateral and vertical variations in the lithology, geology and pore fluid content of the formation materials comprising the stratum.

Abstract: An electronically tuned, optically pumped, transition metal based, solid-state laser is disclosed. Tuning is achieved by using resonant reflecting means comprising an output mirror, a mirror located between the output mirror and the source of laser light, a polarizer located in the light path between the two mirrors, and an electronically tuned, voltage controlled, variable, liquid crystal waveplate for receiving light passing through the polarizer. The components of the resonant reflecting means are selected to have a longitudinal mode that is anti-resonant with the optical cavity of the laser.

Abstract: A curve drilling assembly operable with a rotary drill string is provided for drilling a curved subterranean borehole. The assembly includes a curve guide, a rotary drill bit, an imbalance force assembly, and a bearing assembly. The curve guide is connectable with the drill string for deflecting the drill string toward the outside radius of the curved borehole. The imbalance force assembly, which preferably is provided by selectably disposing cutting elements on the drill bit, is rotatable with the drill string for creating a net imbalance force along a net imbalance force vector substantially perpendicular to the longitudinal axis of the drill bit during drilling. The bearing assembly is rotatable with the drill string and is located in the curve drilling assembly near the cutting elements of the drill bit for intersecting a force plane formed by the longitudinal bit axis and the net imbalance force vector and for substantially continuously contacting the borehole wall during drilling.

Abstract: A chamber in a well is connected to two externally separate tubing strings to unload liquid which is applying backpressure against a formation so that the production of fluid from the formation is obstructed. Volumes of the liquid are intermittently collected in the chamber and lifted out of the well through one of the tubing strings in response to high pressure gas injected solely into the chamber through the other tubing string.

Abstract: A heating probe and collection assembly is provided for evaluating free hydrocarbons and hydrocarbon potential of whole core. In one embodiment, the one or more assemblies are used with a core transport system to provide measures of hydrocarbon potential as a function of depth.

Abstract: Apparatus and method for positioning a tool, such as a surveying instrument, in the deviated section of a borehole includes a flexible rod and a positioning assembly. The flexible rod extends from the vertical section into the deviated section of the borehole with the tool being connected to the downhole end of the rod. The positioning assembly is connected to the uphole end of the rod for positioning the downhole end of the rod in the deviated section of the borehole when the positioning assembly and the uphole end of the rod are in the vertical section of the borehole. In one embodiment, the positioning assembly is a biasing assembly, such as a weight, for urging the downhole end of the rod and tool into the deviated section. In another embodiment, the positioning assembly is an orienting assembly for rotationally orienting the rod and tool in the borehole as the rod is lowered into the borehole.

Abstract: A feedback circuit, comprising: means for producing from a laser light output a feedback signal which is representative of the noise and frequency dependent output intensity of the laser light output; means for applying a phase shift to the feedback signal; means for converting the feedback signal to a level signal which is representative of the noise in the laser light output; amplifying means for amplifying the phase shifted feedback signal as a function of the level signal to produce a current gain signal; and means for superimposing the current gain signal on the current flowing through the laser diode.

Abstract: A predistortion circuit for cancelling third-order distortion products produced by a non-linear device includes a signal source which drives a first and second circuit branch each including a plurality of series connected diodes having approximately exponential transfer functions. The output signal taken as the summation of the two signals processed by the branch circuits is coupled through an amplifier to the device to be linearized. In an alternate predistortion configuration, the signal source drives a phase splitting means which produces two signals of equal amplitude but opposite phase, wherein each of the signals drives a respective one of the branch circuits. A phase combining means performs an out of-phase combination of the signals processed by the branch circuits.

Abstract: A whirl resistant drill bit is disclosed for use in rotary drilling. The drill bit includes a generally cylindrical bit body with a plurality of cutting elements extending out from a lower end surface. The cutter elements are grouped in sets such that a first set of cutters are disposed at substantially an equal radius from a center of the bit body to create a groove in the material being drilled. A second set of cutters is connected to the lower end surface with each cutter therein in overlapping radial relationship with each other and extending a maximum distance from the lower end surface less than that of the first set of cutters. At least one cutter of the second set is in overlapping radial relationship with at least one of the cutters within the first set of cutters. This cutter arrangement causes the drill bit to cut grooves within the formation material that tends to prevent destructive bit whirl. Further, adjustments can be made to vary the back rake angle and side rake angle to prevent bit whirl.