The present invention relates to a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, including a joint, an outer cylinder connected to the joint by thread, a nozzle I mounted in the outer cylinder, a mechanical locking mechanism, a blade telescoping mechanism, an end cap connected to the outer cylinder by thread, a seal ring IV mounted to the end cap, and a nozzle II mounted in the end cap by threaded connection. The present invention achieves integrated operation of conventional drilling and draw-back expanding, which can effectively solve the problems that the existing hydrate drill bit cannot drill a large borehole, cannot mechanically lock an extending position of the blade to stabilize the size of the borehole, and a single crushing method is inefficient.

A hybrid bit with roller cones having inserts is disclosed, includes a bit body, blades and roller cones. All the fixed cutting elements at the inner cone section, nose section and shoulder section of blades herein constitutes two sets of corresponding fixed cutting elements respectively, forming two profile envelopes of fixed cutting elements at least in the interval at the nose section and shoulder section, the two profile envelopes of fixed cutting elements are spaced at high and low intervals at the nose section and shoulder section, forming two stages of cutting by fixed cutting elements; and the cutting position of the cone insert mainly corresponds to the nose section and shoulder section of blades, the outermost cutting profile envelope of cone inserts formed by all or part of cutting elements on cones herein is higher than the outermost cutting profile envelope of fixed cutting elements, forming the third stage of cutting. The invention can effectively develop rate of penetration in hard and plastic formation, maintain and prolong the service life of the hybrid bit, and broaden the formation suitability of the hybrid bit.

A drill bit nozzle assembly and drill bit including the same may include a conical or frustum contoured nozzle body. The nozzle body includes multiple movable closure elements circumferentially arranged to form an inlet orifice, a variable diameter outlet orifice, and a fluid a passage to transport fluid from the inlet orifice to the variable diameter outlet orifice. The nozzle assembly may further include an actuator configured to vary a diameter of the variable diameter outlet orifice based on a change of position of the movable closure elements.

The present disclosure relates to a hybrid bit with roller cone having inserts, comprising a bit body, blades disposed with the bit body, a plurality of fixed cutting elements arranged side by side along the outer edge of blades and roller cones mounted with the said bit body in circumferential and alternate arrangement with the said blades, the said roller cones having multiple rows of cone inserts arranged side by side along the meridian direction of cones, and the said cones having multiple rows of cone inserts arranged side by side along the weft direction of cones, the cutting insert rows of adjacent two cones herein are in alternate arrangement, the cutting insert rows of adjacent two cones are in derangement and the insert placement structure in the plurality of cones is the same.

The present disclosure relates to a hybrid bit with roller cone having inserts, comprising a bit body, blades disposed with the bit body, a plurality of fixed cutting elements arranged side by side along the outer edge of blades and roller cones mounted with the said bit body in circumferential and alternate arrangement with the said blades, the said roller cones having multiple rows of cone inserts arranged side by side along the meridian direction of cones, and the said cones having multiple rows of cone inserts arranged side by side along the weft direction of cones, the cutting insert rows of adjacent two cones herein are in alternate arrangement, the cutting insert rows of adjacent two cones are in derangement and the insert placement structure in the plurality of cones is the same.

A downhole tool string forming a free end portion for performing an operation in a well having a well fluid, the string comprising towards the free end portion; a motor for delivering a rotational speed, a pump connected the motor for circulating the well fluid through a first port and a second port, a gear housing comprising a gear being driven by the pump and delivering a reduced rotational speed, a tool shaft rotatable by the gear at the reduced rotational speed; a reservoir around a section of the tool shaft for collecting dislodged material, and a material dislodging means connected to the tool shaft, wherein the gear housing further comprises a first fluid channel for providing fluid communication between the pump and the first port via the tool shaft being hollow, and a second fluid channel for providing fluid communication between the pump and second port via the reservoir.

A wellbore drill bit includes a body that defines an inner volume and includes a top sub-assembly and is configured to couple to a drilling string, and a plurality of cutting cones along a longitudinal axis of the body. The wellbore drill bit includes a chamber positioned in the inner volume of the body to form an annulus between the chamber and the body; a first set of nozzles positioned in the plurality of cutting cones, each nozzle of the first set of nozzles including a fluid entry that is fluidly coupled to a primary drilling fluid flow path, and a fluid exit oriented toward the second longitudinal end of the body; and a second set of nozzles positioned in the body. Each nozzle of the second set of nozzles includes a fluid entry that is fluidly coupled to the annulus, and a fluid exit oriented toward the first longitudinal end of the body.

Earth-boring rotary drill bits include heel portions exhibiting reduced aggressiveness. Earth-boring rotary drill bits may comprise a bit body and a plurality of roller cones coupled to the bit body. Each roller cone comprises a plurality of rows of cutting elements, and a continuous disk heel located further from an axis of rotation of the roller cone than the at least one row of cutting elements, the continuous disk heel exhibiting a reduced amount of aggressiveness compared to the at least one row of cutting elements.

Earth-boring rotary drill bits include heel portions exhibiting reduced aggressiveness. Earth-boring rotary drill bits may comprise a bit body and a plurality of roller cones coupled to the bit body. Each roller cone comprises a plurality of rows of cutting elements, and a continuous disk heel located further from an axis of rotation of the roller cone than the at least one row of cutting elements, the continuous disk heel exhibiting a reduced amount of aggressiveness compared to the at least one row of cutting elements.

Rotatable elements for use with earth-boring tools include a movable element and a stationary element. The rotatable element may include a void within the support structure and at least one pin protruding from the void through an exterior side of the support structure. The rotatable element may further include at least one aperture configured to provide a vent to the void. The rotatable element may be disposed at least partially within a cavity of the stationary element. The stationary element may further include a track configured to interact with the at least one pin.