Amoco Corporation

The Standard Oil Company

Warren J Winters

Tommy M Warren

J Ford Brett

James F Brett

Michael B Burton

Houston B Mount, Ii

Jame F Brett

Johnie L Landreth

Ernest C Onyia

Marcus A Summers

A method and apparatus for remotely generating pressure signals in a fluid stream for telemetry purposes with minimal insertion loss and susceptibility to blocking flow of the fluid stream by providing a straight through acceleration path for the fluid stream followed by a straight through diffusion path, wherein pressure pulses representing data are generated by turbulence resulting from periodic disturbances made in the diffusion path.

Pressure signalling for fluidic media

Conventional drill pipe is rotated at a rate sufficient for distributing deforming forces substantially uniformly around the circumference of the drill pipe at each location along the length of the drill pipe disposed within the curved portion while the pipe is passed through the curved portion of a short-radius wellbore. The drill pipe arrives in the lateral portion in operable condition for drilling to extend the lateral portion and is retrieved from the wellbore in reusable condition.

Extending the lateral portion of a short-radius wellbore

Rotational orientation of a drillstring is monitored a plurality of times during each rotation of a drillstring for monitoring the rotational orientation of a curve drilling assembly on a drillstring. A defined rotational orientation of a downhole location on the drillstring with respect to the curve drilling assembly is established. At least one reference signal generator having a known relationship to the down hole location on the drillstring and that rotates with the drillstring is provided at the surface. A reference signal is generated each time a reference signal generator rotates past a detector. A pressure signal is generated each time the drillstring rotates through the defined rotational orientation with respect to the drill bit steering device. Occurrences of the plurality of surface reference signals and the pressure signal are timed and compared for monitoring the rotational orientation of the drill bit steering device.

Method of dynamically monitoring the orientation of a curved drilling

A curve drilling assembly operable with a rotary drill string is provided for drilling a curved subterranean borehole. The assembly includes a curve guide, a rotary drill bit, an imbalance force assembly, and a bearing assembly. The curve guide is connectable with the drill string for deflecting the drill string toward the outside radius of the curved borehole. The imbalance force assembly, which preferably is provided by selectably disposing cutting elements on the drill bit, is rotatable with the drill string for creating a net imbalance force along a net imbalance force vector substantially perpendicular to the longitudinal axis of the drill bit during drilling. The bearing assembly is rotatable with the drill string and is located in the curve drilling assembly near the cutting elements of the drill bit for intersecting a force plane formed by the longitudinal bit axis and the net imbalance force vector and for substantially continuously contacting the borehole wall during drilling. Preferably, the bearing assembly includes a substantially smooth wear-resistant sliding surface. The curve guide includes a mandrel rotatably disposed within a housing. A contact ring may be provided at either the uphole or the downhole end of the mandrel for contacting the borehole wall and supporting the radial force component created by the deflection of the drill string at the end of the mandrel. A flexible joint may be connected to the end of the mandrel adjacent the contact ring for drilling curved boreholes having a short radius of curvature.

Apparatus for drilling a curved subterranean borehole

Apparatus and method for positioning a tool, such as a surveying instrument, in the deviated section of a borehole includes a flexible rod and a positioning assembly. The flexible rod extends from the vertical section into the deviated section of the borehole with the tool being connected to the downhole end of the rod. The positioning assembly is connected to the uphole end of the rod for positioning the downhole end of the rod in the deviated section of the borehole when the positioning assembly and the uphole end of the rod are in the vertical section of the borehole. In one embodiment, the positioning assembly is a biasing assembly, such as a weight, for urging the downhole end of the rod and tool into the deviated section. In another embodiment, the positioning assembly is an orienting assembly for rotationally orienting the rod and tool in the borehole as the rod is lowered into the borehole. The orienting assembly also provides for fixing the rotational orientation of the rod and tool with respect to a predetermined point on the circumference of the drillstring and limiting the downhole travel of the rod and tool as the rod is lowered into the drillstring.

Apparatus and method for positioning a tool in a deviated section of a

A method of determining the rotational orientation of a downhole tool on a rotatable conduit, such as a collar on a drillstring in a borehole, without interrupting the rotation of the drillstring, includes establishing the initial rotational orientation of the downhole tool; creating a pressure change to generate a signal; providing a reference point on the conduit; generating a reference signal each time the reference point rotates past a detector; generating the signal each time the conduit rotates through the defined rotational orientation with respect to the tool; and timing and comparing the occurrences of the referenced signal and the signal in order to monitor the rotational orientation of the downhole tool.

Method of determining the rotational orientation of a downhole tool

Apparatus and method for deflecting the drilling direction of a rotary drill string and drill bit through a borehole wall include an anchor, a housing, and a chute. The anchor anchors the apparatus in the borehole. The housing is connectable to the anchor and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the housing. The passageway has an entrance through the uphole end of the housing and an exit through the sidewall of the housing. The chute is slidably disposed in the housing passageway and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the chute from the uphole end through the downhole end. The chute passageway passes the drill bit and drill string through the chute. The chute is movable between a retracted position in which the chute is retracted into the housing passageway and an extended position in which the chute is extended through the housing passageway exit to the borehole wall. The apparatus is inserted into a borehole and anchored, the chute is released to extend into contact with the borehole wall, and the drill bit and drill string are deflectingly passed through the chute.

Apparatus for deflecting a drill string

Apparatus for stabiliing a rotary drill string and drill bit used to drill a borehole in a material, such as a subterranean formation, includes an imbalanced drill collar and a drill bit connected to the drill collar. The imbalanced drill collar creates a drill string imbalance force directed radially outwardly from the center of rotation of the drill collar through a predetermined area on the circumference of the drill collar and urges the predetermined area into contact with the borehole wall as the drill string rotates. The drill bit includes a drilling surface for contacting the material and drilling the borehole in the material, the drilling surface including a cutting zone for cutting the borehole in the material and the bearing zone having a low coefficient of friction relative to the cutting zone. The bearing zone slidingly engages the wall of the borehole as the drill bit rotates and the drill bit is aligned with the drill collar so that the bearing zone and drill string imbalance force are in the same axially-extending radially plane. Preferably, the drill bit is imbalanced to create a drill bit imbalanced force directed radially outwardly from the center of rotation of the drill bit through the bearing zone in the same axially-extending radial plane as the drill string imbalance force.

Method for stabilizing a rotary drill string and drill bit

Apparatus and method for orienting a collar on a fluid conducting conduit, such as a drill string, includes an orifice through the wall of the conduit and a latch assembly for latching the collar to the conduit. The latch assembly allows fluid communication through the orifice and rotates the collar when the conduit is rotated in a first direction about the longitudinal axis of the conduit. The latch assembly unlatches the collar from the conduit, prevents fluid communication through the orifice, and allows the conduit to rotate relative to the collar when the conduit is rotated ion a second, opposite direction. Also included are apparatus and method for rotationally orienting a fluid conducting conduit including an insert connectable inside the conduit so that the insert is rotatable with the conduit; a flow passageway extending through the insert; a pilot passageway extending through the insert; a piston bore in the insert; a piston, reciprocably mounted in the piston bore, for reciprocating between the ends of the piston bore, the piston restricting flow through the flow passageway and creating a fluid pressure increase on the upstream side of the insert when the piston is in a restricted position in the piston bore; and a barrier mass for blocking the pilot passageway in a selected rotational position of the pilot passageway and conduit in order to increase the fluid pressure at the downstream end of the piston bore and move the piston to the restricted position in the piston bore.

Apparatus and method for rotationally orienting a fluid conducting

A method is disclosed for determining rock compressive strength of a subterranean formation penetrated by a wellbore. A mathematical model of a drill bit and an estimate of rock ductility of a particular subterranean formation in conjunction with weight-on-bit (WOB), bit rotational speed RPM, and rate of penetration (ROP) are used as inputs. From the above inputs, the rock compressive strength can be determined while the wellbore is being drilled or afterwards. A depth correlated log can be generated of rock compressive strength that can be compared to other logs obtained from adjacent wellbores to obtain a refined estimate of the depth of a particular subterranean formation feature. Further, the above method can be utilized for obtaining an indication of bit wear or bit damage while the bit is drilling a wellbore by comparing a first rock compressive strength log of a wellbore to a rock compressive strength log being generated while the drill bit is actually drilling a second wellbore. Any significant deviation between the two logs provides an indication of bit wear or bit damage.

Method of determining rock compressive strength

To divert sufficient fluid flow through an unsealed bearing section of a downhole drilling motor, a flow control apparatus is provided for insertion between the power section of the motor and the bottom of a drill bit which is to be turned by the motor. The flow control apparatus includes a variable flow channel having a selectable effective cross-sectional area preferably embodied by a valve. A selected effective cross-sectional area is chosen by a control mechanism, such as a snap ring or a spring used to control the position of a valve member of the valve in response to different flow rates of fluid pumped through the valve depending upon whether the drill bit is on-bottom or off-bottom. In one embodiment the apparatus is incorporated within the interior of a drill bit which has angled flow channels to direct flushing fluid flow to side wall locations where reaming occurs. Flow through these outlets is controlled by positioning of the valve member. The flow control apparatus is part of a borehole excavating apparatus which is a part of a system for drilling a borehole.

Drilling system and flow control apparatus for downhole drilling motors

The orientation of a downhole steering assembly used in drilling a horizontal well is located with respect to the earth using a sub placed above the downhole assembly. The sub comprises a housing having a central bore defining an inlet flow passageway said housing further defining a toroidal chamber in communication with said passageway. The toroidal chamber has a pocket, a valve seat, and a spherical valve that is rotatable in said toroidal chamber from a normally seated position in the pocket. Upon rotation of the drill string the spherical valve plugs the valve seat and causes an increase in the resistance to flow in the drilling mud through the drill string that can be detected at the surface.

Downhole drilling assembly orienting device

To stabilize a drill string and to reduce or prevent wellbore deviation in directional drilling, weight rods by which weight is to be applied to drill bit are maintained free-standing and under compression within a drill string while the drill string itself is maintained in tension to limit or prevent lateral deviation of the weight rods in compression. Weight provided by the weight rods is transferred to the drill bit through a load transfer member in compression connected between the drill string and the drill bit.

Stabilizing and drilling apparatus and method

An excavating system, such as for drilling an oil or gas well, includes a source of high pressure fluid and a drillstring through which the fluid is conducted to an excavating apparatus connected to the bottom of the drillstring. The excavating apparatus includes a drill bit having mechanical cutting elements for mechanically boring into an earthen formation. The excavating apparatus also includes a nozzle rotatably mounted to the body of the drill bit so that the nozzle is rotatable about an axis of rotation different from the axis of rotation of the drill bit. As the drill bit is rotated about its axis of rotation, high pressure fluid is ejected from the nozzle to rotate the nozzle about its axis of rotation while the nozzle orbits the axis of rotation of the drill bit. This combined rotary and orbital motion combined with the positioning of the one or more ports of the nozzle produce a high pressure jet spray scouring substantially all the cross-sectional area engaged by the mechanical cutting elements of the drill bit as the drill bit rotates.

Excavation apparatus, system and method

A downhole drilling apparatus for use with an undergauge drill bit comprises a downhole drilling motor which includes a housing and means for rotating the drill bit relative to the housing about an axis of rotation. The apparatus also comprises stabilizers connected to the housing for stabilizing the drill bit, and it further comprises cutters connected to the housing for cutting a borehole wall created by passage of the drill bit, wherein the cutters extend radially outwardly relative to the axis of rotation to a greater extent than does the drill bit. A drilling assembly including such a drilling apparatus and a method of drilling a substantially vertical borehole in an earthen formation utilizing such an apparatus are also disclosed.

Growing community of inventors

Tulsa, OK, United States of America

Warren J Winters