Mobil Oil Corporation

Duane C Uhri

Alfred R Jennings, Jr

Randy D Hazlett

Robin B Montgomery

A method and apparatus to determine in-situ 'creep' displacement in a cored or drilled borehole. A borehole creep displacement (BCD) tool is suspended into the borehole via a wireline logging cable. Gaging piston fluid forces gaging pistons in a mechanical/electrical assembly of said tool to extend and contact the borehole wall which causes gaging pressure to build. Upon reaching a predetermined pressure, excess fluid flows into a micro-motion fluid distribution body and into an actuator assembly causing an accumulator linear variable displacement transformer (ALVDT) to move thereby causing electrical signals to be transmitted to surface equipment. Once the LVDT has been displaced fully, a closed fluid system within the gaging pistons and a micro-motion assembly is created. Thereafter, any movement of the gaging pistons by the borehole wall will cause fluid motion of a micro-motion cylinder which is attached to a micro-motion LVDT. Movement of the micro-motion LVDT can be read as displacement in thousandths of an inch or as a direct mechanical gain for estimating electrical values.

Borehole 'creep' displacement tool

A method for extending a vertical fracture formed in a formation having original in-situ stresses that favor the propagation of a horizontal fracture. In this method, a subsurface formation having original in-situ stresses that favor the propagation of a horizontal fracture is penetrated by a cased borehole which is perforated at a pair of spaced-apart intervals to form separate pairs of perforations. Fracturing fluid is initially pumped down said cased borehole and out one of said sets of perforations to form the originally favored horizontal fracture. The propagation of this horizontal fracture changes the in-situ stresses so as to favor the propagation of a vertical fracture. Said horizontal fracture is extended by placing a chemical blowing agent and surfactant into the fracturing fluid. Gas released by decomposition of said agent causes foam to be generated along with an increase in pressure thereby extending the horizontal fracture. Thereafter, while maintaining pressure on said horizontal fracture, fracturing fluid is pumped down said cased borehole and out of the other of said sets of perforations to form the newly favored vertical fracture.

Enhanced hydraulic fracturing of a shallow subsurface formation

A process for creating multi-azimuth fractures by hydraulically fracturing a formation via a single wellbore where a special polymer is used as the fracturing fluid. An induced fracture is formed and a solidifiable gel material is injected into the fracture which is allowed to solidify. Thereafter, hydraulic fracturing with the special polymer is repeated causing the fracture trajectory to form contrary to the far-field in-situ stresses.

Creation of multi-azimuth permeable hydraulic fractures

A process and apparatus for simultaneous hydraulic fracturing of a hydrocarbonaceous fluid-bearing formation. Fractures are induced in said formation by hydraulically fracturing at least two wellbores simultaneously. While the formation remains pressurized curved fractures propagate from each wellbore forming fracture trajectories contrary to the far-field in-situ stresses. By applying simultaneous hydraulic pressure to both wellbores, at least one curved fracture trajectory will be caused to be transmitted from each wellbore and intersect a natural hydrocarbonaceous fracture contrary to the far-field in-situ stresses.

Simultaneous hydraulic fracturing

A modified acoustic logging tool to evaluate the condition of a gravel pack is disclosed. Said tool is placed in the wellbore near the gravel pack. An initial log is obtained via said tool at the conclusion of the initial gravel pack treatment. Information gained from the log is indicative of gravel fill and quality. Subsequent logging measurements are indicative of changes in said pack and indicative of remedial treatments.

Method of evaluating gravel packs

A process for sequential hydraulic fracturing of a hydrocarbon fluid-bearing formation. A fracture is induced in said formation by hydraulically fracturing via one wellbore. Thereafter, while the formation remains pressurized from the first induced-fracture operation, a second hydraulic fracturing operation is conducted via another wellbore substantially within the pressurized formation area of the first fracturing operation which causes a fracture trajectory to form contrary to the far-field in-situ stresses. This second hydraulic fracture will tend to curve away from the first hydraulic fracture and has the potential of intersecting natural hydrocarbon fluid-bearing fractures in said formation.

Sequential hydraulic fracturing

A process for sequentially fracturing a subterranean formation containing desired natural resources in which controlled pulse fracturing (CPF) is combined with hydraulic fracturing in the same wellbore. After multiple radial vertical fractures have been created by CPF, a solidifiable gel material is directed into the created fractures during a subsequent hydraulic fracturing procedure. During this procedure, multiple vertical hydraulic fractures initiate in and propagate away from the CPF created fractures thereby bringing the wellbore into communication with the desired natural resources.

Creation of multiple sequential hydraulic fractures via hydraulic

A subsurface formation having original in-situ stresses that favor the propagation of a horizontal fracture is penetrated by a cased borehole which is perforated at a pair of spaced-apart intervals to form a pair of sets of perforations. Fracturing fluid is initially pumped down said cased borehole and out one of said sets of perforations to form the originally favored horizontal fracture. The propagation of this horizontal fracture changes the in-situ stresses so as to favor the propagation of a vertical fracture. Thereafter, while maintaining pressure on said horizontal fracture, fracturing fluid is pumped down said cased borehole and out of the other of said sets of perforations to form the newly favored vertical fracture.

Hydraulic fracturing of a shallow subsurface formation

A subsurface formation surrounding a deviated borehole and having original in-situ stresses that favor the propagation of a vertical fracture is penetrated by a cased borehole. The casing is perforated at a pair of spaced-apart intervals to form a pair of sets of perforations. Fracturing fluid is initially pumped down said cased borehole and out one of said sets of perforations to form a first fracture that is oriented in a direction perpendicular to the direction of the least principal in-situ horizontal stress. The propagation of this first vertical fracture changes the in-situ stresses so as to favor the propagation of a second vertical fracture. This is oriented in a direction parallel to the direction of the least principal in-situ horizontal stress. Thereafter, while maintaining pressure in the first vertical fracture, fracturing fluid is pumped down said cased borehole and out of the other of said sets of perforations to form such a second vertical fracture which will now link naturally occurring fractures in the formation to the deviated wellbore.

Stimulation of earth formations surrounding a deviated wellbore by

The preferred geological orientation of geological formations is determined by geological measurements. These measurements are represented by original vectors which are converted into lineations which represent the extension of the vectors to their intersections with a unit sphere. One of the original vectors is designated as a reference and the half axes of all lineations within 90.degree. of the reference are selected and transformed into unit vectors. The selected unit vectors are vector averaged to produce a resultant vector and the magnitude is determined. The steps are repeated for each of the original vectors and the resultant vector having the maximum magnitude is selected as the preferred orientation of the formation.

Method of determining and displaying the orientation of subsurface

A method is disclosed which allows an overburdened area over an underground mine cavity to be supported by the initiation of foam on liquid retained in the cavity which liquid results from the hydraulic borehole mining of minerals in the cavity.

Use of foam as a borehole ground support system

A hydraulic borehole mining method and device used to recover subterranean coal, oil shale and other minerals from depths exceeding 1500 ft. where a gas lift is utilized to lift the mined slurry to the surface.

Growing community of inventors

Grand Prairie, TX, United States of America

Duane C Uhri