Abstract: A method of fracturing a deep borehole to form a vertical fracture, and of determining the azimuth of the resulting fracture, comprising pumping a pressurized fracture fluid into said well through a pipe from the surface, to provide a bottom hole pressure P which is less than the normal fracturing press (NFP), and generating a series of sharp pressure pulses (SPP) of selected magnitude, such that when added to the pressure P, provide pressure peaks greater than the NFP. By providing arrays of seismic sensors at the surface and determining the direction of propagation of the seismic waves generated by the SPP, the azimuth of the fracture can be determined.

Abstract: This invention relates to a method and apparatus for positioning a selected liquid at the bottom of a well, such as an oil well, while having in the well at least a string of tubing, a sucker rod pump, a string of sucker rods, and a standing valve, without disturbing the rods, pump, tubing, or standing valve. A bypass conduit or shroud surrounds the wall of the tubing at a point above the pump where there is an opening in the wall of the tubing and is carried down, outside the tubing to a point below the conventional mud anchor, into the inlet of an overpressure relief valve. The outlet of the valve empties into the well annulus. If the normal pressure at the bottom of the tubing due to the head of liquid in the tubing is P, the overpressure valve is set to open at a pressure of P+P1, where P1 is a selected value, such as say 100 psi. At the surface, means are provided to close off the top of the tubing.

Abstract: This invention relates to a method of determination of the change in subsurface structure of the earth resulting from the application of fluid pressure at a selected point, at a selected depth, in the earth, by measuring at least one physical parameter of the contour of the surface of the earth above the point of application of fluid pressure. The method involves positioning a plurality of tiltmeters on the earth above the point of application of fluid pressure arranged in a known array, and measuring the change in angle of tilt of the earth's surface at the point of placement of each sensor while varying the pressure and flow rate of fluid into the earth at the selected point. This invention further teaches how the individual values of incremental tilt at selected points on the earth's surface can be processed to provide indication of the azimuth of the vertical fracture in the earth, and an estimate of length of the fracture.

Abstract: An over-the-road type vehicle for transport and powering of a seismic hydraulic vibrator which is adapted to operate in either one of two modes of operation. A first mode is the conventional mode wherein the vehicle is operated over large distances at varying road speeds, obtained by use of multiple gear ratios, and varying engine speeds. The second mode of operation is in a single value of road speed, with engine under control of a governor, to operate at constant high speed, and the movement of the vehicle is by successive short traverses at constant speed. In this second mode of operation the single engine alternately powers the hydraulic vibrator, and with the engine still at high speed, then moves the vehicle to a new vibration point a short distance away. A high energy efficiency is provided by the use of a mechanical, rather than hydraulic drive system, and a high time efficiency is provided by a novel style of clutch that can start the vehicle from rest with the engine at maximum speed.

Abstract: A data acquisition and transport system including a plurality of array terminals, each array terminal having a plurality of geophones delivering analog signals thereto, the analog signals being digitized to 1-bit and temporarily stored, and on demand, transmitted downline to a recording station, as a train of 1-bit pulses. The array terminals have two identical ports into which cable segments of two conductor digital transmission channels can be plugged. Means are provided in the recording station to place a DC potential between the two terminals of the digital transmission channel. In the array terminals means are provided for identifying which of the two identical ports is the one which receives the DC potential, which is identified as the downline port. On receiving a DC potential at the downline port, a corresponding DC potential is transmitted through the upline port to the next array terminal and so on.

Abstract: A dispenser for well treating chemicals for pumping oil wells, for attachment to the bottom end of the tubing string, comprises a long cylindrical container, closed at top and bottom, about the same diameter as the tubing and rigidly attachable to the bottom end of the tubing. The bottom end of the chamber is preferably pointed, with at least one opening in the bottom end. The chamber is filled with chunks of solid chemical, of a nature normally used for treating wells. In the normal pumping action, the weight of the well fluid filling the tubing to the surface is supported by the sucker rods during that part of the pumping cycle when the rods are moving up. When the rods are moving down, the weight is carried by the tubing. This varying load on the tubing causes it to lengthen under load, and shorten, so that the bottom end of the tubing raises and lowers through a range of a foot or more.

Abstract: A linear explosive charge with constant detonation velocity, comprising a plurality of series-coupled explosive units or sticks. All sticks are identical and comprise a tubular member of selected length, with matched couplings. A helix of explosive cord is positioned around the tubular member, with ends inserted through openings into the interior of the tube and out through the couplings. At the top end of the stick a length of elastic tube is inserted, over the projecting cord, into the top coupling. When two sticks are to be coupled, the downward projecting cord of the top stick is inserted into the elastic tube along side the starting end of the cord of the second stick. This stretches the tube, which presses the two cords into intimate cross-detonation condition. Small ring-shaped concentrated explosive units can be inserted into the bottom end of the top stick over the explosive cord, as synchronous booster charges.

Abstract: A linear explosive charge with constant detonation velocity comprising, a plurality of separate similar sticks that can be axially coupled into a long linear substantially rigid assembly. Each of the sticks includes a helical winding of linear explosive cord on its outer surface, the ends of the cord are coupled to the ends of the cord on adjacent sticks, so as to carry the detonation of the cord from one stick to the next. Separate booster explosive charge units are coupled into each of the junctions between sticks, to provide additional explosive units which are synchronously detonated by the passage of the cord detonation from stick to stick.

Abstract: An underground combustion operation in which combustible material, in a selected geologic formation at a selected depth, is burned by forcing air under pressure down a first well into the formation, and collecting products of combustion at a second well, a selected distance away from the first well. The overburden above the formation is supported, in part, by the combustible material, which might be viscous oil, tar, etc. This material is ignited at the first well and a flame front is formed which burns in the form of a circular front, which moves radially outwardly as a function of time and the rate of air supply. A plurality of electronic tilt meters are positioned at or near the surface of the earth, in at least one linear array directed along the radius from the first well to the second well. Combustion air is provided and the outputs of the tilt meters are amplified and recorded as a function of time.

Abstract: In the process of recovering minerals, such as hydrocarbons from shallow tar sands, and the like, one method is to create a shallow horizontal fracture within the tar sand. The size and shape of the perimeter is determined, and one or more secondary boreholes are drilled to the formation inside of the perimeter of the fracture. Pressurized air is injected into the fracture and the hydrocarbons are ignited. After a selected period of burning is carried out, the radius to the burn front, surrounding the recovery area, from which the hydrocarbons have been removed, is determined by placing a source of seismic waves at a selected point over the fracture, and a long array of seismic sensors colinear with the source.The source is energized for different conditions of pressurization in the formation and fracture. The reflected seismic waves are converted to electrical signals, which are compared for all sensors.

Abstract: A seismic method for mapping horizontal fractures in the earth resulting from the application of fluid pressure, at a selected point, at a selected depth, in the earth, comprising the steps of creating a seismic wave in the earth over the expected position of the fracture, and detecting the seismic waves reflected upwardly at a reflecting interface, at or near the fracture, at each of a plurality of seismic sensors, in at least one radial array. The received signals are recorded for each of two conditions: a first case, when the fracture is pressurized, and filled with fluid, and the roof of the fracture is separated from the base of the fracture; and a second case when the fracture is depressurized, and the roof of the fracture rests on the base. Some sensors will show a different character of reflection signal in the two cases. For these sensors the points of reflection are within the outer perimeter of the fracture.

Abstract: This invention relates to a method of determination of the change in subsurface structure of the earth resulting from the application of fluid pressure at a selected point, at a selected depth, in the earth, by measuring at least one physical parameter of the contour of the subsurface of the earth above the point of application of fluid pressure. The method involves positioning a plurality of tiltmeters on the earth above the point of application of fluid pressure arranged in a known array, and measuring the change in angle of tilt of the earth's surface at the point of placement of each sensor while varying the pressure and flow rate of fluid into the earth at the selected point.

Abstract: This invention relates to a method and apparatus for positioning a selected liquid at the bottom of a well, such as an oil well, while having in the well at least a string of tubing, a rod pump, a string of rods, and a standing valve, without disturbing the rods, pump, tubing or standing valve. A bypass conduit is connected through the wall of the tubing at a point above the pump and is carried down, outside the tubing to a point below the conventional mud anchor, into the inlet of an overpressure valve. The outlet of the valve empties into the well annulus. If the normal pressure at the bottom of the tubing due to the head of liquid in the tubing is P, the overpressure valve is set to open at a pressure of P+P1, where P1 is a selected valve, such as say 100 psi. At the surface, means are provided to close off the top of the tubing. Means are provided to inject the selected liquid into the top of the tubing at a selected pressure P2 above atmospheric, where P2 may be say 150 psi.

Abstract: A foldable linear explosive charge (FLEC) comprising a plurality of similar tubular members which are hinged to each other at their ends so that they can be extended co-linearly to form a long tubular member or can be hinged and relatively rotated 180.degree. from each other to form a zig-zag folded system suitable for transport or storage. While in extended form, with the tubular members co-linear, they are wound with a helix of linear explosive compound (LEC). At the joints between each pair of tubular members, the LEC passes directly over the hinge, so when that joint is rotated from closed (folded) to open (linear) position, the explosive member is not moved, except for a rotation, in which it returns from a slight torsion. The FLEC is carried in a container in the folded condition and when it is to be inserted into a drilled shot hole, each successive pair of sticks is unfolded into a co-linear position and lowered into the shot hole.

Abstract: A system and method for carrying out seismic operations with low energy sources, which involves operating the source at spaced points along a seismic spread, the source points are spaced far enough apart so that their seismic waves originate at different points and travel by different paths to the geophones. The geophone outputs cannot be time stacked. The geophone signals are amplified at constant gain and digitized to 1 bit. If the low energy source is a vibratory source, the 1 bit signals are correlated with a 1 bit version of the sweep signal. The resulting correlograms are digitized to 1 bit and C.D.P. stacked and displayed. If the low energy source is impulsive, the 1 bit amplified signals are C.D.P. stacked and displayed. In C.D.P. stacking, the determination of optimum velocity can be carried out by 1 bit processing.

Abstract: A simplified cable system for use in gathering S analog signals into each of T array terminals (AT), spaced apart a distance D, where the analog signals are amplified, digitized, stored and, on command, transmitted as trains of digital bits along a digital conductor pair in the cable system, to successive ATs downline, to a recording unit. In the optimum embodiment, the cables are all identical, are plugged into each of 2 ports, or receptacles, in each AT. The cables are D/2 long, have S/2 conductor pairs, and S/2 takeouts spaced D/S apart, each takeout connected to a different conductor pair. Each cable contains at least one digital conductor pair. Two cables in series connect between adjacent ATs. The plugs joining one cable to the next, connect only the digital conductor through from cable to cable, while the analog conductor pairs are dead ended at the joining plugs.

Abstract: In the field of the storage and retrieval of information, information records in the form of patterns of microspots of small size and high packing density are formed on a record web by the use of a focussed first laser beam, of a first level of intensity, to evaporate or burn away material to form microperforations in a thin layer of opaque first material on a web of transparent plastic. This invention covers the process of preparing a facsimile record of the pattern of microspots on a master record by exposing a second record web through the microperforations in the first web to a constant intensity focussed second laser beam of less intensity than the first level of intensity. Also means are shown for using an optical pattern on a first layer to control a laser to burn openings into an opaque underlying layer.

Abstract: The method of determining the magnitude of the differential static correction between adjacent records in seismic record processing, that involves the steps of: recording a first multi-trace record responsive to a first seismic wave generated at a first source point; recording a second corresponding multi-trace record responsive to a second seismic wave at a second source point, which is adjacent to the first source point; correlating a first trace of the first record with the corresponding first trace of the second record, and determining the first time difference between the two first traces of said two records; repeating the correlation step and determining the time differences for a plurality of N pairs of traces; adding all of the N time differences and dividing the sum by N to find the net difference in static correction between the first and second source points.

Abstract: The method of determining the magnitude of the differential static correction between two selected adjacent receiver points D, E, in a linear seismic array, that involves the steps of: recording a first multi-trace record responsive to a first seismic wave generated at a first source point C on one side of D, E at any distance; recording a second corresponding multi-trace record responsive to a second seismic wave at a second source point F on the opposite side of D, E at any distance; correlating a first trace CE with a second trace CD of the first record to obtain a first time difference R; correlating the corresponding first trace FD with a second trace FE of the second record to get a second time difference S; and determining the value of K = (R - S)/2, where K is a value of the static correction equal to the difference in the travel time through the weathered layer at D and E. The process can be repeated for other positions of C, F to obtain other independent values of K.

Abstract: A system and method for carrying out seismic operations with low energy sources, which involves operating the source at spaced points along a seismic spread, the source points are spaced far enough apart so that their seismic waves originate at different points and travel by different paths to the geophones. The geophone outputs cannot be time stacked. The geophone signals are amplified at constant gain and digitized to 1 bit. If the low energy source is a vibratory source, the 1 bit signals are correlated with a 1 bit version of the sweep signal. The resulting correlograms are digitized to 1 bit and then C.D.P. stacked and displayed. If the low energy source is impulsive, the 1 bit amplified signals are C.D.P. stacked and displayed.