摘要:
Methods, systems, and apparatus for inducing fractures in a subterranean formation and more particularly methods and apparatus to place a first fracture with a first orientation in a formation followed by a second fracture with a second angular orientation in the formation are provided. First and second fractures are initiated at about a fracturing location. The initiation of the first fracture is characterized by a first orientation line. The first fracture temporarily alters a stress field in the subterranean formation. The initiation of the second fracture is characterized by a second orientation line. The first orientation line and the second orientation line have an angular disposition to each other.
摘要:
A downhole tool for fracturing a subterranean formation according to which a tool having a plurality of discharge jets or nozzles is located in a spaced relation to a wall of the formation to form an annulus between the nozzles and the formation. An acid-containing, stimulation fluid is pumped at a predetermined pressure through the nozzles, into the annulus and against the wall of the formation. A gas is pumped into the annulus so that the stimulation fluid mixes with the gas to generate foam before the mixture is jetted towards the formation to impact the wall of the formation. The tool is adapted to bend, or tilt, so that the discharge jets can come in to proximity to the formation being fractured.
摘要:
Apparatus and method for controlling an unswept volume in a piston system. The method includes rotating a shaft around a rotation point to drive a piston within a cylindrical volume in a periodic manner, modifying the stroke length of the piston, and moving the center of the shaft relative to the cylindrical volume such that a change in an unswept volume or compression ratio is controlled.
摘要:
A method of fracturing a downhole formation according to which a plurality of jet nozzles are located in a spaced relation to the wall of the formation to form an annulus between the nozzles and the formation. A non-acid containing stimulation fluid is pumped at a predetermined pressure through the nozzles, into the annulus, and against the wall of the formation, and a gas is introduced into the annulus so that the stimulation fluid mixes with the gas to generate foam before the mixture is jetted towards the formation to form fractures in the formation.
摘要:
A pressure activated bendable tool assembly having a longitudinal centerline, the tool assembly comprising an adapter sub for connection to an end of a tubular member having a bore extending longitudinally therethrough and a plurality of bend elements positioned in a serial relationship also having a bore extending longitudinally therethrough, the bore being in fluid communication with the bore of the adapter sub and each adjacent bending element. The bend elements are axially retained by a plurality of retainer sleeves. The retainer sleeves limit the amount the bend elements may be longitudinally displaced from each other about a preselected side of the retainer sleeve element. A head-sub forms a distal end of the tool assembly opposite of the adapter sub. The tool assembly bends with respect to the longitudinal centerline a preselected amount upon inducing a pressure differential between the respective bores of the adapter sub, the bend elements, and the head-sub and the ambient pressure of the tool assembly.
摘要:
Expandable casing portions are provided, such as casing slip joints or expansion joints, on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. The fracture initiation location may be provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. These slots may be formed by a hydraulic jet which is directed through the opening and then pivoted generally about the point of the opening. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells, but are also useful on vertical wells.
摘要:
A set point pressure control circuit is disclosed for controlling pressure in a high pressure environment. The circuit includes a high pressure communicating, low pressure actuated valve. The valve includes a housing in which a valve member is disposed. The valve member has an axial passageway defined therethrough for communicating a high pressure port across a piston of the valve member to an opposite high pressure chamber which is placed in communication with a low pressure port when the valve member is in an open position.
摘要:
A pressure controller includes a set point switch mechanism by which a selectable pressure to be maintained in a pressure vessel can be set. The actual pressure in the pressure vessel is detected and converted into a corresponding electrical signal by a suitable pressure transducer. Electrical signals from the set point switch mechanism and the transducer are utilized by a computer to generate control signals for controlling a volume adjustment mechanism which adjusts the effective volume of the pressure vessel and adjusts the quantity of pressurizing fluid disposed in the vessel. The volume adjustment mechanism includes a piston disposed in a cavity which is connectable with the chamber of the pressure vessel. The volume adjustment mechanism also includes a stepper motor which can be moved in precise increments to adjust the position of the piston in the cavity.
摘要:
Systems and methods for multi-lateral wellbore construction and stimulation from cased parent wellbores. Methods and apparatus are provided to facilitate the creation of casing exit openings in the casing of parent wellbores. Methods and systems are provided for azimuthally and longitudinally aligning drilling assemblies through openings in a parent wellbore casing are provided to allow for drilling multiple lateral wellbores extending outwardly from a parent wellbore. A method of stimulating one or more subterranean zones intersected by multiple lateral wellbores extending outwardly from one or more parent wellbores includes the steps of: simultaneously injecting a stimulation fluid into the lateral wellbores; and stimulating the zones intersected by the lateral wellbores in response to the stimulation fluid injecting step.
摘要:
A method of locating a wellbore feature, comprising delivering a mechanical position determination tool into the wellbore, selectively causing an undulating curvature of the mechanical position determination tool in response to a change in a fluid pressure, moving the mechanical position determination tool along a longitudinal length of the wellbore, and sensing a change in resistance to continued movement of the mechanical position determination tool. A mechanical position location tool for a wellbore, comprising pressure actuated elements configured to cooperate to selectively provide an unactuated state in which the mechanical position location tool lies substantially along a longitudinal axis and the pressure actuated elements further configured to cooperate to selectively lie increasingly deviated from the longitudinal axis in response to a change in pressure applied to the mechanical position location tool.