Downhole electrical core drilling system

Claim 2

Improvements for downhole electrical core drilling systems particularly the type suspended in a well hole by an electricalmechanical cable and basically consisting of a core bit attached to the downhole end of a core barrel the uphole end of the core barrel attached to and operated by a speed reduction transmission powered by a downhole electric motor and a core break-off or cutoff mechanism contained inside of the core barrel, wherein the improvements comprise: a drill collar, the downhole end of the drill collar is attached to the uphole end of the electric motor, a cable connector attached to the uphole end of the drill collar and to the electrical-mechanical cable, the mechanical part of the electrical-mechanical cable is attached to the cable connector and the electrical part of the electrical-mechanical cable extends through the center of the cable connector down through the hollow center of the drill collar and connects to the uphole end of the electric motor, an improved core cut-off and catching mechanism that cuts a drilled core off and holds said core inside of the core barrel, the said core cut-off and catching mechanism is contained inside of the core barrel, an activating apparatus contained inside of the core barrel activates and operates the said core cut-off and catching mechanism, a latching apparatus contained inside of the core barrel keeps the activating apparatus disengaged until a core has been drilled, a latch releasing apparatus contained inside of the core barrel is activited by interfacing with the uphole end of a drilled core and when activated releases the latching apparatus so the activating apparatus will engage and operate the said core cut off-and catching mechanism, a improved anti-torque device which consist of a flexible wire coil which encloses the electrical-mechanical cable and wound to off set back torque and hold the electrical-mechanical cable stright when the electric motor is operating, the downhole end of the flexible wire coil is connected to the uphole side of the cable connector.

Claim 3

In claim 1 one or more holes are drilled in the wall of the core barrel near the uphole end of the core barrel so drill cuttings and fluids can be exhausted from the core barrel when a core is being drilled or when the downhole electrical core drilling system is being lowered into a well hole.

Claim 4

In claim 1 a mounting plate is attached to the inside wall of the core barrel near the uphole end of the core barrel and the latch releasing apparatus is mounted on the downhole side of the mounting plate, the latching apparatus and activating apparatus are mounted on the uphole side of the mounting plate, the core core-cut off and catching mechanism is activated when the desired length of core has been drilled and part of the weight of the downhole electrical core drilling system rest on the uphole end of the drilled core that interfaces with the latch releasing apparatus which supports the said weight on the uphole end of the drilled core and when said weight reaches the desired amount the latch releasing apparatus disengages the latching apparatus, the latching apparatus when disengaged engages the activating apparatus which activates and operates the core cut-off and catching mechanism which cuts off the drilled core and holds said core in the core Barrel while the downhole electrical core drilling system is hoisted to the top of the well hole, a core cut-off and catching cable which is apart of the core cut-off and catching mechanism is attached to the activating apparatus and at a point on the inside wall of the core barrel near the core bit.

Claim 5

In claim 3 the latch releasing apparatus consist of a solid flange plate which is slightly less in diameter than the diameter of the drilled core and the center of the solid flange plate corresponds with the center of the core barrel, the flat downhole side of the solid flange plate interfaces with the uphole end of the drilled core, a swivel joint, a square plug and the downhole end of the swivel joint is attached to the center of the uphole flat side of the solid flange plate and the uphole end of the swivel joint is attached to the downhole side of the square plug, the swivel joint lets the solid flange plate interface with the uphole end of the drilled core and remain still while the core barrel is rotating, a square rod attached to the center of the downhole side of the mounting plate, a compression spring attached to the downhole end of the square rod, the downhole end of the compression spring is attached to the center of the uphole side of the square plug, a square tube which encloses the compression spring and slips over half of the square rod, the downhole end of the square tube is closed by and attached to the uphole side of the square plug, a mounting arm, a latch releasing rod, one end of the mounting arm is attached to the square tube and the other end is attached to the downhole end of the latch releasing rod, a hole in the mounting plate from the uphole side to the downhole side of the mounting plate is placed so the latch releasing rod can extend through the hole and interface with the latching apparatus, the uphole end of the latch releasing arm is angled and concaved to provide a releasing interface with the latching apparatus, when the solid flange plate interfaces with a drilled core and the desired weight of the downhole electrical core drilling system shifts from the core bit to the solid flange plate the compression spring compresses and the square tube slips farther over the square rod and the latch releasing arm interfaces with the latching apparatus and disengages the latching apparatus.

Claim 6

In claim 3 the latching apparatus which keeps the activating apparatus disengaged while a core is being drilled consist of a mounting support which is mounted on the uphole side of the mounting plate, a latch arm which is a flat metal bar, the downhole end of the latch arm is hinged to the mounting support, a hinge bolt which hinges the mounting support to the latch arm, one side of the latch arm interfaces with the activating apparatus, a catch is made in the side of the latch arm that interfaces with the activating apparatus and is the part of the latch arm that interfaces with the activating apparatus, the part of the side of the latch arm between the catch and the downhole end of the latch arm is convexed and is the part of the latching apparatus that interfaces with the latch releasing apparatus, when the latch releasing apparatus acts on the latch arm the interface between the catch of the latch arm and the activating apparatus is broken and the activating apparatus engages, a holding spring which has one end attached to the mounting support and the other end attached to the latch arm, the holding spring acts on the latch arm to maintain the catch interface with the activating apparatus.

Claim 7

In claim 3 the activating apparatus which activates and operates the core cutoff and catching mechanism consist of a square guide rod and the downhole end of the square guide rod is attached to the center of the uphole side of the mounting plate, a round flange plate, a square hole in the center of the round flange plate large enough to slip over the square guide rod, an activating spring and the uphole end of the activating spring interfaces with the downhole sIde of the round flange plate, the downhole end of the activating spring interfaces with the uphole side of the mounting plate, the activating spring is mounted so the square guide rod will be in the center of the activating spring, the overall diameter of the activating spring is slightly less than the diameter of the round flange plate, a square guide tube which is large enough to slip over the square guide rod, the downhole end of the square guide tube attaches to the uphole side of the round flange plate around the square hole, an activating arm having one end attached to the square guide tube, part of the downhole side of the activating arm near the end attached to the square guide tube is attached to the uphole side of the round flange plate, the end of the activating arm not attached to the square guide tube is attached to the core cut-off and catching mechanism, the activating apparatus is disengaged by applying downhole pressure on the square guide tube until the activating spring is compressed to the point where the latching apparatus interfaces with the uphole side of the round flange plate and holds the activating spring in a compressed state, the activating apparatus stays lock in this position while a core is being drilled, when the latch releasing apparatus acts on the latching apparatus the interface between the uphole side of the round flange plate and the latching apparatus is broken and the activating apparatus engages, when the activating apparatus engages the activating spring applies and maintains an uphole pressure on the round flange plate, square guide tube and activating arm, the activating arm activates and operates the core cut-off and catching mechanism by applying and maintaining an uphole pulling force on the core cut-off and catching mechanism.

Claim 8

In claim 3 the core cut-off and catching mechanism consist of an end clamp that attaches to the inside wall of the core barrel near the point where the downhole end of the core barrel interfaces with the core bit, a counter sunk hole in the end clamp, a threaded hole in the inside wall of the core barrel, a clamp bolt that fits through the counter sunk hole and screws into the threaded hole attaching the end clamp to the inside wall of the core barrel, a round guide tube attached on the inside wall of the core barrel, the overall diameter of the round guide tube is slightly less than the distance from the inside wall of the core barrel to the side of a drilled core, the round guide tube extends from near the point where the downhole end of the core barrel interfaces with the core bit to the mounting plate, the round guide tube is attached to the inside wall of the core barrel so that the downhole end of the round guide tube will be one hundred and eighty degrees around the intercircumference of the core barrel from where the end clamp is mounted, a slot in the side of the mounting plate running from the downhole side of the mounting plate to the uphole side of the mounting plate is located directly over the uphole end of the round guide tube, two or more wall clamps are attached to the inside wall of the core barrel between the downhole end of the round guide tube and the end clamp, the downhole end of the cut-off and catching cable is clamped to the inside wall of the core barrel by the end clamp, the cut-off and catching cable extends into the downhole end of the round guide tube up through the round guide tube, through the slot in the mounting plate, the uphole end of the cut-off and catching cable is attached to the activating apparatus, when the activating apparatus is disengaged the cut-off and catching cable is held against the inside wall of the core barrel between the downhole end of the round guide tube and the end clamp by the wall clamps, when the activating apparatus is engaged and the activating apparatus provides an uphole pulling force on the uphole end of the cut-off and catching cable and is pulled from the wall clamps and against the drilled core, one or more abrasive sections of abrasive matErial is adhered to the section of the cut-off and catching cable that interfaces with the drilled core, the pulling force on the said cable and the rotation of the core barrel causes the abrasive sections to cut the drilled core until the said cable extends directly from the end clamp to the downhole end of the round guide tube at which point the drilled core will be cut off and the said cable extending directly under the cut off drilled core will hold said core in the core barrel.