Abstract: A method for determining a parameter by combination of engineering models and statistical analysis of drilling data in a data base to determine the frequency or probability of sticking of the drill string during drilling of wells at hole-angles from vertical to horizontal. The parameter can be used to decrease the probability of sticking of drill string during drilling a well and to minimize the cost of a well.

Abstract: Ball sealers comprising a polyetheretherketone are introduced into a well to seal well perforations and divert fluid therein. In the preferred embodiment the ball sealers have a density less than the treating fluid.

Abstract: A combination low-pressure, high-pressure hydraulic pump which allows a constant differntial pressure is disclosed. This pump features dual concentric pistons, each with its own chamber. The pistons reciprocate together at low pressures; as the system pressure increases, a spring resists the stroke of the low pressure piston, so that ultimately only the smaller, high pressure piston reciprocates.

Abstract: A process for determining an end member age of an illite component in an earth sample which contains a diagenetic illite component and a detrital illite component. As a first step, the sample is separated into a plurality of fractions so that the fractions will have different mean ages of illite. Next, the relative percentage of one of the illite components is determined for each fraction. The mean age of total illite in each fraction is determined using potassium-argon age analysis. The determined relative percentages are then correlated with the determined mean ages to generate a linear relationship. The end member age for each illite component can then be determined by using the linear relationship since zero percent of one of the illite components corresponds to the end member age of the other illite component.

Abstract: A method for determining drilling fluid density for stabilizing a wellbore including obtaining shale cuttings from a wellbore. In one embodiment of a method according to this invention, shale cuttings are obtained from a wellbore and their index properties, including but not limited to surface area, is measured; mean effective stress around the wellbore is calculated using the geostatic overburden in situ stress, the field pore pressure, and the total stress around the wellbore; the in situ shale strength is determined using a correlation between surface area, mean effective stress and shale strength; and drilling fluid density is determined using the shale strength. Methods for determining in situ shale strengths, elastic properties, pore pressures, and formation stresses of low permeability rocks.

Abstract: Controlled phase marine seismic subarray for use in a marine seismic array and methods for constructing such subarray are provided. A controlled phase marine seismic subarrays of the present invention are arranged to operate at a preselected depth and to provide generally downgoing (for angles of emergence from the array that are of interest) far-field pulses having phase spectra that match the phase spectrum of the vertically downgoing far-field pulse up to a ghost-notch frequency. The methods select the depth of operation and type of sources for the subarray, select a maximum number of identical elements and spacing based upon the highest incidence angle and frequency for which phase control is desired, and construct a plurality of parallel, linear, subarrays.

Abstract: A downhole seismic acoustical signal source capable of selectively firing numerous, prewired explosive charges. The downhole seismic source has a firing system that uses a sequence of combinations of two conductors at a time and a downhole diode array to select and fire a single charge. The conductors are connected to a Surface Control Unit at the surface. A seismic crew on the surface can select and fire any charge through this control unit. The downhole seismic source has the ability to fire numerous explosive charges in a given downhole trip through the firing of many individual explosive charges.

Abstract: Methods and apparatuses for testing the effects of one or more fluids on geologic materials; in one aspect a method for quantitatively determining the hydration and swelling behavior of shale core samples in response to one or to different fluids circulated around a core sample confined under pressure in a test cell; apparatuses for circulating such fluids and for conducting such tests; and an adjustable LVDT holder.

Abstract: Disclosed is a process for increasing the selectivity in converting sulfates to sulfonates following ethoxylation and sulfation of alcohols. It is demonstrated that minimization of unethoxylated and monoethoxylated alcohols before the sulfation step will substantially reduce hydration to alcohols and increase the selectivity of the subsequent sulfonation step.

Abstract: Method and apparatus for generating resonant broad band pressure waves in a fluid-filled wellbore for seismic exploration. In the preferred embodiment, a device is provided in a borehole; the device comprises a cylindrical choke body and a means at each end of the choke body for partially or completely blocking off the borehole and creating a fluid-filled borehole cavity. The fluid inside the cavity is oscillated to establish a standing pressure wave of a desired bandwidth in the fluid. The standing wave is radiated through the wellbore into the earth formation and is received by seismic detectors. The fluid is oscillated over a range of frequencies to generate more information about the earth formation.

Abstract: A process for obtaining ethane and propane refrigerant from a lean feed gas is disclosed. Said process involves the addition of a small amount of propane to a stream of said lean feed gas, thus widening the phase envelope and increasing the ease of separation of the methane and nitrogen from heavier components.

Abstract: Methods and apparatuses for measuring ultrasonic velocities in materials are disclosed which, in one embodiment, include such methods and apparatuses for triaxial tests of low permeability rock samples, the apparatus including top and bottom end caps for mounting to a sample to be tested, each end cap having an ultrasonic transducer mounted therein for disposition in contact with the material to be tested for measuring the velocities of ultrasonic waves through the material. In another embodiment, at least one end cap having channels and a sensor for sensing changes in sample pore pressure is disclosed. In another aspect, a pressure generator or microaccumulator for changing the amount of a pore pressure fluid in the channels, thereby changing sample water content and making possible an efficient multistage test is disclosed. In another embodiment an end cap for such measurements is disclosed.

Abstract: An elongated bubble cap tray allows three phases: solid, vapor and liquid, to come in contact at the bottom of a controlled freezing zone and transfer heat and mass amongst themselves. Complete melting of the solid phase may be achieved in this tray, significantly reducing or totally eliminating the need for an external source of energy as well as its associated heat transfer equipment.

Abstract: A module model pile tool in situ testing of soils. The tool has an upper instrument section, a lower anchor section, and an axial slip joint located between the instrument section and the anchor section. The anchor section may be configured to model either open-end or closed-end piles. In the open-end configuration, a vent and vent valve are provided to vent trapped fluid during the initial stages of installation by remaining open only to a predetermined depth so as to permit formation of an undisturbed soil plug and to close in order to prevent fluids from being vented into the actual soil to be tested. The instrument section includes instrumentation for measuring axial loads, axial accelerations, pore water pressure, and total lateral pressure. Instrumentation for measuring axial displacement are included in the slip joint. The tool is rugged enough to permit installation by pile driving, and the instrumentation may be monitored both during and after installation.

Abstract: A process for dewatering an aqueous fluid containing solids using water-absorbent substances is disclosed. A water-absorbent substance and a body to which the solids will adhere are added to the solids-containing aqueous fluid. The water-absorbent substance absorbs water and the solids coat the solids-adhering body. The water-laden substance may then be separated from the solid-adhering body that is coated with solids, thereby separating the water and the solids.

Abstract: A tether for securing a buoyant structure to the ocean floor. The tether includes a cable or a plurality of cables whose weight is at least partially supported by a buoyancy tank.

Abstract: A drill bit drilling a borehole is used as a strong high frequency, subsurface seismic source in combination with at least one receiver in a preexisting borehole to determine the continuity of a subsurface formation layer extending between the borehole being drilled by the drill bit and the borehole in which the receiver is located. The receiver(s) in the preexisting borehole may be any conventional seismic receiver or receivers, such as hydrophones or geophones. The receiver or receivers are positioned in the preexisting borehole at a depth adjacent the formation layer whose continuity is to be determined. The depth (position), velocity and thickness of the layer is determined from a conventional well log of the preexisting borehole. A frequency power spectrum for a preselected frequency range (the range is selected based on the logging data) may be computed from the signals recorded by the receiver(s).

Abstract: A seismic source for downhole use is disclosed which is formed by an outer tubular member having weighted ends which carries within a coaxially mounted tubularly shaped piezoelectric element. The piezoelectric element is cyclically driven to produce a standing wave having a frequency in the range of 0.25 to 5 kHz and a narrow bandwidth in the range of 5-50 Hz.

Abstract: A method for removing dissolved solids or sludge from amine absorbing solutions for acidic gas in gas sweetening systems is provided comprising contacting a stream of regenerated absorbing solution with CO.sub.2 such that the sludge forms a precipitate and removing the precipitate from the absorbing solution. The stream of absorbing solution may then be returned to a regenerator for removal of CO.sub.2 or returned to the gas sweetening system with the regenerated absorbing solution.

Abstract: A threaded connection with improved fatigue-life useful for connecting adjacent sections of a pipe string subject to bending, tensile, and compressive stresses such as a drill collar string is disclosed. The connection comprises a pin member which is threadedly engageable with a corresponding box member. In the preferred embodiment, the inventive connection is designed to have bending strength ratio ("BSR") of about 3.20 or greater, and more preferably, in a range between about 3.20 and about 4.00. The preferred thread form of the connection is a V-type thread form having two flank angles of 30 degrees and a 0.038 inch root radius. Other design features may be used in combination with the threaded connection to further improve the connection's fatigue-life.