Abstract: A method for suppressing noise in a common depth point gather of seismic data traces is disclosed in which noisy data traces are detected and muted by a sequence of data processing steps prior to making a final stack of the data traces.

Abstract: A method and apparatus are disclosed for processing seismic trace data to distinguish Class II sand formations sandwiched between low and high porosity layers, where the intermediate sand layer causes a polarity reversal with offset in seismic reflections. A velocity analysis of data from a vertical seismic section is generated to include coherency contours corresponding to polarity reversals in the seismic traces by using an extended crosscorrelation algorithm for multi-trace coherency. The velocity analysis thus indicates a stacking velocity that will maximize coherency of the seismic traces exhibiting the polarity reversal.

Abstract: A method to rapidly characterize the hydrocarbon chemistry of heavy residual petroleum mixtures uses three model equations for predicting aromatic carbon content, aromatic hydrogen content and total hydrogen content of the heavy residual oil. The predictive equations are based on three easily measured bulk properties including refractive index, specific gravity and the Watson K factor.

Abstract: A computer implemented method for mapping seismic attributes derived from analysis of isochron measurements is disclosed. According to the disclosed method planar surfaces, which model the upper and lower surface of a subterranean layer, are numerically inserted in a seismic data volume with the edges of the planar surfaces connecting reflection events of a three-by-three array of seismic traces. Using the model surfaces, isochron attributes are calculated including the amount of isochron thickening or thinning in the direction of dip, and the azimuth of maximum thickness change. The thus calculated attributes are written to data cubes, which can be displayed in a variety of ways.

Abstract: In an HF alkylation process where an acid catalyst regeneration column separates HF acid from ASO and water to provide regenerated catalyst for a catalyst circulation stream, and where buildup of ASO in the catalyst circulation stream is encountered, an improved control scheme uses an on-line analyzer/controller to maintain desired concentrations of HF acid, or ASO or water in the catalyst circulation stream. In one embodoment, a continuously flowing catalyst slip stream is piped to the analyzer/controller for simultaneously determining concentration of HF acid, ASO and water, and in a preferred embodiment the ASO concentration is maintained at a desired low level by manipulating temperature of a stripping fluid charged to a lower section of the column. An alternate manipulated variable is temperature of the acid catalyst feed to the regenerator column. Alternate controlled variables are the HF acid, and water concentration in the catalyst circulation stream.

Abstract: A computer implemented method for analyzing seismic data to discover a real trends of multi-attributes in a seismic data volume is disclosed. According to the disclosed method and apparatus the full waveforms of multiple traces are compared in a zone that extends above and below an interpreted horizon, and the comparisons are made using a correlation algorithm that considers both shape and absolute amplitude of the waveforms being compared. Based on the multiple comparisons, traces are classified according to waveform shape such that maps of common waveform classes show areas of similar lithology and/or hydrocarbon effects.

Abstract: An enlarged computer graphic image of seismic data is displayed on a concave three-dimensional surface having a shape corresponding to the shape of selected data extracted from a three-dimensional seismic volume. Thus providing an enlarged image of a seismic surface where the data is spatially correct in three-dimensions, and which increases the ease with which interpreters can locate geological features such as horizons, faults, and channels.

Abstract: An effective laboratory method for developing complete capillary pressure curves involves directly measuring an oil/water saturation profile within a cylindrical porous rock core plug. The saturation profile, which includes a free water level, is established under a known pressure gradient induced by centrifuging and is measured using image mapping techniques. The free-water level is established at a desired position within the length of the core plug and provides a reference position of zero capillary pressure to facilitate measurement of both positive and negative capillary pressures.

Abstract: A computer implemented method and apparatus for discovering hydrocarbon bearing formations yields a direct indication of hydrocarbon resulting from analyzing seismic amplitude data. The method uses an algorithm for determining a seismic attribute known as delta amplitude dip (DAD) in which each sample point of each seismic trace in a survey is analyzed to determine a planar dip associated with the reflection point and a normalized delta amplitude in the direction of dip. Displaying the DAD values in time slice or horizon slice format provides a direct indicator of hydrocarbons. The inventive method automatically analyzes each digitized data point in the survey by cross correlating the traces reflected from a three-by-three array of reflection points. This method involves cross correlation of eight traces that are reflected from the perimeter of the three-by-three array of reflection points with the single trace reflected from the central point in the array.

Abstract: The time required for establishing a multilateral well is reduced by enlarging a section of a wellbore and running a multilateral tool into the enlarged wellbore section. The multilateral tool, which is suitable for running into a wellbore on a primary casing string, includes a preassembled combination of casing sections that are used to form dual casings strings extending from the primary casing. The multilateral tool incorporates three casing sections, which maintain the diameter of the primary casing, including: a carrier section, a lateral section, and a main section. In use, the tool is run with the lateral section releasably held in coaxial alignment within the carrier section, and with the main casing section fixed to the lower end of the carrier section. Once in place in the enlarged section of the wellbore, the lateral section is released and diverted out of a preformed window in the lower end of the carrier section and runs generally parallel to the main casing section.

Abstract: An improved method for gathering traces in a 3-D seismic survey is disclosed. In one configuration, receiver lines having equally spaced geophone receivers stations are run in one direction, and lines of equally spaced shotpoint stations run orthogonal to the receiver station lines. The station spacing in each shotpoint and receiver lines is selected to produce a desired spatial resolution, and the individual lines are spaced apart by a distance equal to at least two times the station intervals. In this method, a series of common mid point gathers centered about source/receiver line intersection, referred to as "hybrid gathers" is made, where each hybrid gather includes traces from a designated number of shots in the shotpoint line of the selected intersection that are directed into a designated number of geophone receivers in the receiver line of the selected intersection.

Abstract: A computer implemented method and apparatus is disclosed for automatically picking faults in a recorded 3D seismic trace data volume. The method employs test planes, which are mathematically inserted into the seismic data volume to approximate dip and azimuth of a potential fault plane surface. A large number of data points, which are selected points on the seismic traces, are defined within the seismic volume, such that each test plane positioned in the seismic volume contains data points corresponding to at least a significant portion of a trace. The method then determines a factor for each data point which is representative of the probability that the data point resides on a fault plane. This probability is based on planar discontinuity and average amplitude difference between corresponding traces in adjacent parallel test planes, and the method selects locations, in an x, y grid, of a strip of locations having high probability of residing on a fault surface.

Abstract: A fitting for coupling a service line to a polyethylene fluid distribution pipe such as a water main or a gas main includes a stub length of polyethylene pipe that serves as a base for attaching a corporation stop valve. The cross section of the open base end is machined to match the curvature of the outside surface of the main pipe and then fused into the sidewall of the main. The corporation stop valve can then be used for hot tapping polyethylene mains.

Abstract: A downhole tool facilitates in-situ borehole measurement of stress required to initiate a fracture in a desired direction in subterrean formation. The tool is constructed by longitudinally splitting a cylinder in half, and in use the tool includes an inflatable packer disposed within the split cylinder to force each half of the split cylinder against the borehole wall when the packer is inflated. Each half of the split cylinder, which serves as a borehole platen, is made to better conform to an irregular surface of a borehole wall by dividing the split cylinder into multiple segments that are loosely joined so as to allow limited independent movement of each segment with respect to adjacent segments.

Abstract: A well reasoned steady state model for simulation of pentane isomerization in a long tubular reactor predicts important reaction variables such as feed conversion, product yields, temperature and pressure. The predictions are based on inputs including feed flowrates, composition, temperature and pressure. The model includes a set of differential equations for component concentrations with respect to axial distance along the reactor, and reaction rate constants expressed in terms of physical properties. A method of programming a computer for simulating the reaction is disclosed.

Abstract: Harmonics, which appear with seismic reflection signals and are responsive to actual vibrations of a land-vibrator for petroleum exploration, are effectively utilized in pulse compression techniques by applying a correlation operator (CO) signal representative of the actual vibrations injected into the earth. In the invention, the CO signal may be acquired by detecting the motion of the baseplate of the land vibrator. Signal correlation procedures are then used to define an inverse filter whose output is pulse-like in response to the CO signal, and the reflected signal is applied to the inverse filter to yield a pulse compressed signal including harmonic energy.

Abstract: A compact hot-tap saddle pipe fitting made of weldable plastic material integrates a branch saddle and a tubular adapter into a monolithic tee shaped unit. The fitting, which is characterized by short overall dimensions and a reinforced base portion, allows a fully pressure rated connection of a branch line to a main plastic pipeline using an isolation valve and a standard size hot-tap cutting tool.

Abstract: A fiber reinforced cement lining for an unconsolidated or otherwise problematic zone in a wellbore is built up by first under-reaming the section of the wellbore to be stabilized by the cement lining. Next a drillable metallic liner is centralized in the under-reamed section and the annulus formed between the metal liner and the wellbore wall is filled with the fiber cement. After the cement has hardened, the drillable liner and a portion of its surrounding cement are milled out using the drillable liner as a guide for a piloted mill tool, thus leaving a relatively uniform thick-walled cement sheath bridging the zone to be stabilized in the wellbore while restoring the original diameter of the wellbore through the unconsolidated zone.

Abstract: A computer implemented method for modeling and simulating a hydrotreating reactor is disclosed where a first step in the simulation utilizes a computer data base of reaction kinetic parameters for hydrotreating sulfur and metals contaminated residuum and gas oil fractions. The data base is extended to include parameters and physical properties for residuum and gas oil fractions that are obtained from several different source locations. A group of equations, which are functions of catalyst properties, reactor parameters and feedstock composition, models the reaction by predicting yields, hydrogen consumption, contaminant levels, and physical properties of the reactor product. The simulation adjusts the kinetic parameters for reaction conditions to be simulated, such as temperature, catalyst activity, hours on stream, space velocity etc., and solves the model equations for the desired results.

Abstract: A method and apparatus for predicting distribution of reservoir permeability or porosity and pseudo relative permeability using well data and 3-D seismic data are disclosed, where a preferred first step in the method models the reservoir property of interest to provide model logs which are expressible as continuous curves of a reservoir property as a function of depth. The next step selects individual data points on the continuous curves traversing a reservoir layer and determines permeable trends for a multitude of column-like subvolumes which each enclose a portion of the selected data points. The subvolumes are then divided into a desired number of horizontal slices, with each slice containing a number of the model data points. An average value for the property in each slice is calculated, and the average values are plotted versus depth for each subvolume, thus providing a derived curve of depth versus the reservoir property.