Abstract: Sand control screens temporarily plugged with paraffin wax are installed in deep open hole wells wherein the wax has a melting temperature slightly greater or less than the nominal formation temperature in the zone from which well fluids are to be produced. Drilling fluids and other solids-laden wellbore fluids are removed from the wellbore by flowing the well up through a section of tubing disposed distal of the screen, through the interior of the screen and through the tubing string to the surface until the wellbore is cleaned. The wax is then melted due to the temperature of the produced fluid, is dissolved by the produced fluid or a solvent pumped down through the tubing string or is heated by a heater inserted into the interior of the screen such as a wireline conveyed electric heater. The distal tubing section is plugged so that production fluids are forced to flow through the sand control screen in a conventional manner.
July 28, 1992
Date of Patent:
February 22, 1994
Atlantic Richfield Company
H. Mitchell Cornette, Stephen E. Morrison
Abstract: An offshore mooring buoy for mooring a crude oil tanker and the like includes a hawser tension sensing member and a control circuit for generating indicator signals in response to predetermined mooring tension forces exerted on the buoy under varying sea conditions. A mast mounted on a mooring platform of the buoy includes a vertically-spaced array of colored indicator lamps which provide visual indication to the ship's crew of a range of acceptable, stand-by, and unacceptable mooring loads exerted on the buoy and the hawser. The circuit is also operable to energize a horn when a predetermined sustained mooring force is exerted on the buoy as a back-up signal or when weather conditions impair visual observation of the indicator lamps.
Abstract: Deposits are removed from cargo tanks of marine crude oil tankers and the like by introducing into the tanks a solvent for the deposits which are formed on the interior surfaces of the tanks, including those surfaces which cannot be reached by crude oil washing machines and the like. The solvent is caused to contact all of the interior surfaces of the tanks by pumping ballast water sequentially into and out of the tanks to cause the solvent to rise and fall in each of the tanks. The method may be carried out during return trips of tankers from the point of discharge of cargo to the point of loading new cargo.
Abstract: Hydraulic fractures are initiated or extended into fluid-producing earth formations from a cased well by filling a space within the casing adjacent the formation zone of interest with liquid which extends into a tubing string and forming a pressure gas charged portion of the tubing string by introducing pressure gas or liquid into the tubing string to compress a column of gas therein to a pressure which exceeds the formation fracture breakdown pressure. By perforating the casing or, if perforations already exist, releasing a frangible disk type closure interposed in the tubing string, the gas charge in the tubing string forces fluid into the formation at sustained pressure and flow conditions not attainable by surface pumped fracture fluids.
April 27, 1992
Date of Patent:
December 21, 1993
Atlantic Richfield Company
Joseph H. Schmidt, James C. Abel, J. Lawrence Bacak, Dennis R. Reimers, Ching H. Yew
Abstract: Wellbores are formed in the earth with elongated, tubular drillstems which include retrievable bit assemblies. The retrievable bit assembly includes a body having locking dogs engageable with cooperating recesses formed in a sub at the bottom of the drillstem. The bit assembly includes radially extendable and retractable arms with cutters thereon for forming the wellbore to a diameter greater than the drillstem, but whereby the arms may be retracted to withdraw the bit assembly through the drillstem with wireline retrieval apparatus or the like. The wellbore may be drilled with a tubular drillstem comprising wellbore casing with a bit connected to the lower end of the drillstem and retrievable through the drillstem by the wireline retrieval apparatus whereby the casing may be left in the wellbore upon completion of drilling operations.
Abstract: A well conduit cutting and milling apparatus conveyable into and out of a well on coilable tubing using a tubing injection unit. The apparatus includes tubing or casing cutting arms which are radially extendable and retractable with respect to a cylindrical support body by pressure fluid operated pistons. The apparatus is made up of multiple end-to-end connected units including one which supports interchangeable cutting and milling arms and units which have radially extensible and retractable stabilizing arms which engage the inner wall of the tubing or casing to centralize and stabilize the apparatus during operation. The cutter and milling arms are modified for milling away a section of tubing by moving the apparatus in an upward or out of the well direction. The cutting elements are preferably cylindrical hard metal members which are supported on the arms for cutting away an end face of the tubing in a tangential direction of movement.
March 25, 1992
Date of Patent:
November 30, 1993
Atlantic Richfield Company, Charles D. Hailey
David D. Hearn, Charles M. Hightower, Stephen L. Ward, Charles D. Hailey
Abstract: Floating roof storage tanks are modified to include a foam surge tank, a low-pressure blower and a foam generator for generating vapor-suppressing foam during withdrawal of liquid from the storage tank and after the floating roof reaches its lowest elevation in the storage tank so that the tank space previously occupied by volatile liquid is provided with a vapor-suppressing foam blanket during liquid withdrawal and refill. The surge tank is mounted directly on the floating roof and discharges its foam through an opening in the roof into the tank storage space. During liquid refill the foam may be forced out through a vent conduit onto the roof of the tank and dissolved and recovered.
Abstract: A closure gate for a coal-loading chute has opposed flat plate closure members for controlling the flow of coal from a storage bin to transport vehicles and the like. Each closure member is provided with opposed seal assemblies engaged with opposed surfaces of the closure member to prevent leakage of coal dust. The seal assemblies comprise elongated, spaced-apart support plates for supporting an abrasion-resistant, plastic seal member characterized by an elongated flat plate which is supported between the seal assembly support plates and is spring biased into engagement with the closure member.
Abstract: Multiphase (gas and two liquid phases) fluid flowstreams are measured to determine the total flow rate, fluid density, the fraction of gas, and one liquid in the total liquid mixture by passing the flowstream through a volumetric or mass flow meter (16, 40), a densimeter (12) and a meter (14) which measures the fraction of one liquid in the two liquid mixture. The total fluid flow rate may be measured by a single tube flow meter (40) having adjacent loops which provide tube legs (49, 51) positioned adjacent each other and vibrated laterally at a predetermined frequency and amplitude while measuring pressures in the contraflowing streams in the adjacent tube legs. The density and gas fraction of the flowstream may be determined by vibrating a tube containing the flowstream over a range of frequencies and measuring the phase angle and amplitude of the fluctuating fluid pressures compared with acceleration of the tube to determine the sloshing natural frequency of the fluid mixture.
Abstract: The particle volume and particle mass production rate of particulate solids entrained in fluid flowstreams such as formation sand or fracture proppant entrained in oil and gas production flowstreams is determined by a system having a metal probe interposed in a flow conduit for transmitting acoustic emissions created by particles impacting the probe to a sensor and signal processing circuit which produces discrete signals related to the impact of each of the particles striking the probe. The volume or mass flow rate of particulates is determined from making an initial particle size distribution and particle energy distribution and comparing the initial energy distribution and/or the initial size distribution with values related to the impact energies of a predetermined number of recorded impacts. The comparison is also used to recalibrate the system to compensate for changes in flow velocity.
Abstract: Oil and gas well production flow is gathered in field common line manifolds and conducted through a separator to make a coarse separation of gas from liquid and minimize slug flow in the conduits leading from the manifolds to further separation, treatment and pumping facilities. A liquid level signal transmitter provides a signal to a valve controller which controls separate liquid and gas discharge flow control valves or a variable speed pump to maintain a set point level of liquid in the separator. Liquid level control is accomplished automatically by varying the flow from the fluid discharge conduit which is connected to the lower pressure flow line, which is usually the gas flow line. Manifold pressures may be sensed to prevent exceeding a predetermined pressure in the manifolds and the well flow lines.
Abstract: Water injection wells are fractured by a proppant-laden fracturing fluid to create a propped fracture and wherein the proppant-laden fluid is followed by injection of a substantially proppant-free fluid so that the near wellbore portion of the fracture is free of proppant to minimize pressure drop during water injection and to produce higher injection rates for a given injection pressure. The fracture treatment may include the use of viscous fracturing and displacement fluids which are degraded by the injection of acid-bearing fluids at the end of the fracture treatment cycle. Stimulation or displacement liquid (water) injection may commence immediately after the fracture treatment and may be alternated with miscible gas injection.
Abstract: Marker dyes are detected in aged and dirty or "brown" gasolines by passing a sample of gasoline through plural solid phase extraction columns including a first column having a strong anion exchange phase bonded to a silica substrate. A color-forming reagent is added to the first column after elution of the gasoline sample therethrough. The marker dye colored complex and colored bodies not retained on the first column are eluted into a nonpolar solid phase extraction column with methane-sulfonic acid and the marker dye colored complex is eluted through the second column and into and through a third column containing unbonded silica. The color bodies of the gasoline will remain on the columns and the marker dye will be detectable at the bottom of the third column as evidenced by a pink color for marker dyes such as Morton International Mortrace MP marker dye and the like.
Abstract: The concentration of detergent additives and the like in motor gasoline and similar liquid petroleum fuels is measured by evaporating a sample of the fuel and passing the sample through a light-scattering detector to measure the concentration of unevaporated particles of high molecular-weight, low volatility material present in the additive concentrate. A gasoline sample may be passed through the detector by a transport medium comprising one of heptane and iso-octane. Photo detector signals generated by the additive-containing sample are compared with signals detected with samples not containing any additive. The sample and the transport medium are condensed after analysis. The method is fast, does not require venting of volatile hydrocarbon fluids to atmosphere and may be carried out using a minimal quantity of fuel product as the sample.
Abstract: Systems for determining the gas compression exponent, k, and the compressibility factor, Z, include a chamber which may be reduced in volume while the pressure, temperature and volume changes are recorded. The system for determining compressibility factor includes a temperature controller and heat exchanger which varies the temperature in the chamber after a compression process or while holding the volume of the chamber constant during multiple temperature changes. Values of pressure, temperature and volume are measured at all conditions. The compression exponent is measured by extrapolating a curve of pressure versus time while allowing the temperature of the gas to decay from heat exchange with the structure forming the chamber.
Abstract: Under-balanced or potential fluid cross-flow conditions in a wellbore are minimized during installation of an auger-type gravel pack screen by placing a quantity of fine salt, calcium carbonate paste, a fluid loss control gel or sand within the interior space of the screen liner so that the material will form a substantially impermeable barrier on the liner, the gravel packing or the face of the formation during or after installation of the screen to minimize fluid flow in wells which have a relatively high pressure gradient. The material may be removed at will by circulation of a dissolving liquid such as fresh or unsaturated water or mechanical removal of insoluble material such as sand.
Abstract: Liquid storage tank level sensing gauge floats may be retrieved from within the tank without entry of personnel into the tank by a device comprising spaced apart pairs of pivotally-supported hook members which are engagable with guide arms or other support members of the float, upon lowering the device into the storage tank, whereby the float is grappled by the retrieval device for retrieval to the roof or top of the tank from outside the tank. The opposed pairs of hook members may be retained on a support rod by retaining collars which have slots for engagement with float guide rods or cables to further control the path of movement of the device during retrieval operations.
Abstract: Slurried solid waste materials are injected into subterranean earth formations in a zone of interest which has a relatively low in situ compressive stress bounded by zones of higher in situ compressive stress and wherein the zone of interest has alternate layers of material of relatively high and low permeability to fluid flow, respectively. The solid waste slurry is conducted through an injection well penetrating the zone of interest to form a conventional two-winged hydraulic fracture. The fracture is extended by reducing the tendency to form filtercake in the fracture adjacent to the layers of material of relatively low permeability while depositing particle filtercake adjacent the earth layers of high permeability so as to provide clear fluid flowpaths through the fracture while allowing the filtercake layers disposed in the fracture to assist in propping the fracture open until adequate lateral extension of the fracture and disposal of the waste material is accomplished.
Abstract: Multiphase (gas and two liquid phases) fluid flowstreams are measured to determine the total flow rate, fluid density, the fraction of gas, and one liquid in the total liquid mixture by passing the flowstream through a Ceriolis flow meter (16, 40), a densimeter (12) and a meter (14) which measures the fraction of one liquid in the two liquid mixture. The total fluid flow rate may be measured by a single tube flow meter (40) having adjacent loops which provide tube legs (49, 51) positioned adjacent each other and vibrated laterally at a predetermined frequency and amplitude while measuring pressures in the contraflowing streams in the adjacent tube legs. The density and gas fraction of the flowstream may be determined by vibrating a tube containing the flowstream over a range of frequencies and measuring the phase angle and amplitude of the fluctuating fluid pressures compared with acceleration of the tube to determine the sloshing natural frequency of the fluid mixture.
Abstract: A whipstock adapted for insertion into a wellbore through a tubing string having a smaller diameter than the wellbore casing or the open hole portion of the wellbore includes a setting mechanism comprising extendable legs which engage the wellbore wall to bias the whipstock into a position of inclination of the whipstock guide surface relative to the wellbore axis. The setting mechanism includes an actuating rod which may be actuated by a conventional downhole tool setting device to extend and retain the legs in their extended position. Cooperating ratchet means and tensionable couplings on the setting mechanism including a frangible coupling part permit actuation of the whipstock to its set position and retrieval of the setting device. The whipstock is releasable from the setting device by an adaptor having cooperating ball keys engageable with an adaptor actuating shaft and the upper end of the whipstock body.