Abstract: A Petragrid method and apparatus generates grid cell property information that is adapted for use by a computer simulation apparatus. An interpretation workstation includes at least two software programs stored therein: a first program called "Petragrid" and a second simulation program for generating a set of simulation results for display. The first Petragrid software program will: receive well log and seismic data which indicates each layer of a formation, grid each layer of the formation where the grid is comprised of a plurality of cells, and generate more accurate data associated with each grid cell, such as the transmissibility. The more accurate data for each cell will be transmitted to the second simulation program which will respond by generating a set of more accurate simulation results for each cell of the grid, and overlaying the more accurate simulation result for each cell onto each of the corresponding cells of the grid being displayed on the workstation display by the Petragrid software.

Abstract: An integrated data communication and data access system includes a first cache memory operatively connected to a first application and a first conversion means operatively connected to the first cache memory and interfacing between a first operator of the first application and the first cache memory for receiving original data having a first format from the first operator and converting the original data having the first format into original data having a second format, the first application storing the original data having the second format in the first cache memory and in a database when the first application sets a persistant or a transient storage state.

Abstract: A Petragrid method and apparatus generates grid cell property information that is adapted for use by a computer simulation apparatus which simulates properties of an earth formation located near one or more wellbores. An interpretation workstation includes at least two software programs stored therein: a first program called "Petragrid" and a second simulation program which is responsive to output data produced from the first "Petragrid" program for generating a set of simulation results. The set of simulation results are displayed on a workstation display monitor of the workstation. The first Petragrid software program will: receive well log and seismic data which indicates the location of each layer of a formation near a wellbore, and then grid each layer of the formation, the grid being comprised of a plurality of cells. The first Petragrid software will then generate more accurate data associated with each cell, such as the transmissibility of well fluid through each cell.

Abstract: An operator sitting at a workstation views, on a display, a multitude of seismic traces having one or more horizons indicated therein by a plurality of sets of events (such as peaks or troughs or zero crossings) on the seismic traces. The operator uses a mouse to draw a line from left to right across a plurality of seismic traces being displayed on the workstation display screen. At this point, the line does not lie on the events (such as the peaks) of the seismic traces. Therefore, the line does not yet represent a horizon in an earth formation. The operator presses a key on the keyboard of the workstation. In response to the pressing of this key, the workstation processor executes a "snapper software" in accordance with the present invention.

Abstract: An automatic, non-artificially extended, fault surface based horizon modeling method and apparatus produces a final faulted horizon model which is a three dimensional representation of a faulted earth formation including all the horizons and all the faults in response to seismic data, well log data, and fault surfaces and relationships data. The horizon modeling apparatus produces the final faulted horizon model by filtering input horizon data and removing bad (wrong-sided) data points.

Abstract: Formation tops correlation is interpreted between sampled log curves by a weighted combination of covariance, the ratio of standard deviation, and the ratio of summed amplitude. This covariance function is computed and evaluated appropriately for the geologic environment over a sliding analysis window. Correlations are determined for any number of wells and any number of events in each well. Geologic rules are used to establish a parameter for the algorithm operation and for the analysis of the resulting function. The geologic rules include bounding guide horizons, sequence rules, and a covariance cutoff parameter. Bounding horizons are picked from pre-existing seismic or geologic interpretations and from map grids. The rule set includes onlap, truncated, conformable, and unstructured sequence definitions. Additional geologic complexity such as crossover, repeat sections, and inverted sections are accommodated by the rule set.

Abstract: An interpretation workstation based apparatus having an "Auto Fault" software stored therein automatically identifies a plurality of fault cuts in each of a plurality of horizons in a seismic data volume in response to a plurality of predetermined "horizon time structures".

Abstract: A method and associated apparatus for generating time slice maps and/or horizon maps, representative of a time slice or a horizon in an earth formation that is subject to a seismic operation, in response to received seismic data includes the steps of: (a) cross correlating a plurality of seismic traces from the seismic data and a corresponding plurality of quadrature traces associated, respectively, with the plurality of seismic traces to obtain a corresponding plurality of cross correlation functions "Q(.tau.)", (b) obtaining a plurality of particular values from the plurality of cross correlation functions "Q(.tau.)", at least one particular value being obtained from each cross correlation function, and (c) assigning the plurality of particular values to a respective plurality of reflection points on a map, each particular value being assigned to a different one of the reflection points, thereby constructing the time slice map and/or the horizon map.

Abstract: A novel fault framework method and apparatus automatically computes the relationships between intersecting fault surfaces. When faults are loaded into the novel fault framework apparatus, all intersecting fault pairs are determined and the fault fault intersection lines are computed and stored. The intersecting fault pairs are presented and available for automatic calculation of the major/minor and above/below fault pair relationships. The geometry of both intersecting fault surfaces are examined on either side of the fault fault intersection line. This, in combination with the relative size of the faults, is analyzed to compute the major/minor and above/below relationships based on geologic assumptions and knowledge of the origin of the fault surface data. When the relationships between intersecting faults is defined, the minor fault is appropriately truncated.

Abstract: A processing system stores a special software known as the Cubemath software. The Cubemath software allows the processing system to process, analyze, and interpret a second set of seismic data relative to a first set of seismic data obtained from either a repeat seismic operation or a single seismic two processing method operation. A first set of 3D seismic data is collected at a particular location on the surface of the earth at time "t1", and a second set of 3D seismic data is collected at that same particular location on the surface of the earth (at a different time "t2" when the repeat seismic operation is being performed).

Abstract: A valve for use downhole in a wellbore can be repeatedly opened and closed any number of times in response to a pressure signal transmitted down the annulus of the wellbore. The valve is set and changes from a first position to a second position in response to a first pressure signal transmitted down the annulus, a pressure value of the first pressure signal transmitted down the annulus being greater than a pressure value of a pressure existing in an inside annular space of the valve by an amount at least equal to a predetermined value. The valve resets itself and changes back from the second position to the first position in response to a second pressure signal transmitted down the annulus, the pressure value of the pressure existing in the inside annular space of the valve being greater than a pressure value of the second pressure signal transmitted down the annulus by an amount at least equal to the predetermined value.

Abstract: A valve adapted to be disposed in a wellbore for use during a drill stem test includes one or more rupture discs which, when ruptured by one or more annulus pressures or a tubing pressure, moves a mandrel in either of two different longitudinal directions. When the mandrel is moved, one of four possible events could occur. First, a pair of flapper valves will close, and, after the pair of flapper valves close, a reversing port will open. Second, a ball valve will successively close and open and, simultaneously, a reversing port will successively open and close. Third, a port will move into congruence with a one-way check valve allowing a fluid to flow from within an internal area within the valve to an external area around the valve. Fourth, a port will move out of congruence with a one-way check valve thereby preventing a fluid from flowing from the external area around the valve to an internal area within the valve.

Abstract: A new zonal isolation method and apparatus perforates a plurality of zones of a formation, while isolating each perforated zone from every other zone, with one trip into wellbore, and without requiring the circulation of a kill fluid throughout the wellbore following perforation to kill the well so that a packer and/or a perforating gun may be removed from the well. The new zonal isolation apparatus includes a perforating gun and a plug or packer connected to the perforating gun. The new zonal isolation method includes detonating the perforating gun thereby creating a set of perforations in the formation; moving the perforating gun and plug/packer uphole until the plug/packer is situated at a particular position in the wellbore which is disposed directly above the set of perforations in the formation; and setting the plug/packer at the particular position in the wellbore.

Abstract: A multiple wellbore tool apparatus consisting of a plurality of microprocessor implemented wellbore tools is disposed in a fluid filled wellbore, and an input stimulus having a predetermined signature propagates down the wellbore fluid to all of the wellbore tools. The plurality of wellbore tools each include a microprocessor implemented controller board as well as an included wellbore tool and an acoustic receiver transmitter transducer connected to an output of the controller board. In addition, each of the microprocessors of each controller board include a memory which stores its own unique microcode programming. In response to the input stimulus, the controller board of a first wellbore tool determines that a correspondence exists between the signature of the stimulus and information stored therein and generates an output signal.

Abstract: A packer assembly adapted to be disposed in a wellbore includes a packer and a packer lock apparatus, the packer lock apparatus including a lock and release apparatus for locking the packer in an unset condition, releasing the lock on the packer which locks the packer in the unset condition when the packer is lowered into a smaller diameter casing in the wellbore, allowing the packer to begin changing from the unset condition to a set condition, and a time delay apparatus for requiring a predetermined time period to elapse, following the release by the lock and release apparatus of the lock on the packer, before the packer can be fully changed from the unset condition to the set condition. As a result, the entire packer will be disposed within the smaller diameter casing before the packer is fully set.

Abstract: A perforating gun includes a multiplicity of shaped charges, the multiplicity of shaped charges including a plurality of planes of charges, each plane of charges including a plurality (N) of shaped charges and a detonating cord running down through the axial center of each of the plurality of planes of charges. The plurality (N) of shaped charges are equally spaced at an angle 360/N about the detonating cord. The plurality of planes of charges: (1) are rotated at an angle of 180/N relative to one another, and (2) are axially packed together along the longitudinal axis of the gun so that the charges in one plane are nearly touching the charges in the adjacent plane, yet they all share the same centered detonating cord. The proximity of one plane to another is close enough such that one plane of charges detonates within a few microseconds of its neighboring plane of charges.

Abstract: A new induction logging tool has a toolstring length that is shorter than the toolstring length of the induction logging tool of the prior art. The new induction logging tool includes a new induction array which appears to be folded about an axis that coincides with the transmitter of the induction array of the prior art induction logging tool. The new folded induction array including a transmitter coil, located at an end of the new folded induction array, and a plurality of "cowound" receiver coils and bucking coils, a further plurality of individual receiver coils, and at least one further bucking coil located adjacent to and on one side of the transmitter coil of the new folded induction array.

Abstract: A pressure containing wireline sheave mechanism having a sheave body defining an opening within which is received a sheave housing which cooperates with the sheave body to define a circular internal sheave chamber which is exposed to operating pressure such as well pressure during well servicing activities. A split sheave having an external wireline groove is located within the internal chamber and is rotatably supported at its inner periphery by bearings. During operation of the wireline sheave mechanism lubricant is supplied to the inner periphery of the internal sheave chamber at a location adjacent the bearing and at a lubricant pressure exceeding well pressure to prevent well pressure induced migration of contaminants from the wireline groove of the sheave to its bearings.

Abstract: A shaped charge includes a main body of explosive and a primer adapted to detonate said main body of explosive. In accordance with the present invention, the main body of explosive now includes an explosive composition known as sym-triaminotrinitrobenzene (TATB) and, since TATB is not sensitive enough to be a primer, the primer must consist of an explosive composition which is more sensitive than TATB. It has been discovered that, when the main body of explosive in a shaped charge is modified to include the explosive composition known as TATB and when the primer includes an explosive other than TATB, such as HNS or NONA or PYX or HMX, or a mixture of HNS or NONA or DODECA or PYX or HMX and TATB and when the shaped charge is detonated, the detonated charge will produce a jet that is longer in length than the jet associated with prior art shaped charges which did not have a main body of explosive that included TATB.

Abstract: A logging apparatus is adapted to be disposed in a mud filled wellbore, and a measurement probe is connected to a bottom of a tool string of the logging apparatus. The measurement probe is adapted for measuring a resistivity of a mud in the mud filled wellbore. The measurement probe includes a bottom electrode disposed on a bottom of the probe when the logging apparatus is disposed in the wellbore, a second electrode, and at least one measurement electrode disposed adjacent the bottom electrode for measuring a voltage potential drop in a region of the mud which is disposed directly below the bottom electrode of the measurement probe when the probe is disposed in the wellbore. When the measurement probe is energized, a current flows in the mud between the bottom electrode and the second electrode.