China University of Petroleum

Yongwang Liu

Zhichuan Guan

Yucai Shi

Hualin Liao

Ben Guan

Jilei Niu

Yandong Yang

Hongning Zhang

Weixing Yang

Sen Wei

Zhonghai Zhou

Zhixiang Teng

Chenglin Fu

Wenzhong Wei

Zhibin Fan

Deyong Zou

Zaiqiang Miao

Can Yi

Yuqiang Xu

Huaigang Hu

The present invention provides a bottom-hole impact-rotation stepping combined unloading rock-breaking efficient drilling system, including a housing, a drive assembly, a universal joint, a transmission shaft, a rotational impact assembly, and a drill bit; the transmission shaft is connected with the housing; the rotational impact assembly includes a rotational transmission assembly for conveying a rotational power to the drill bit and an impact assembly for providing a high frequency axial impact power to the drill bit; when the rotational transmission assembly rotates along with the transmission shaft, the impact assembly applies a high frequency impact force along a drilling axial direction to the rotational transmission assembly; an annular drill bit is disposed at an outer end of a drill bit body of the drill bit; a central drill bit is slidably disposed on an inner ring end surface of the annular drill bit; an inwardly-recessed cylindrical region is formed between a head end of the annular drill bit and a head end of the central drill bit. The present invention further provides a bottom-hole impact-rotation stepping combined unloading rock-breaking efficient drilling method. In the present invention, with entire structural disposal, stepping rock-breaking, bottom hole unloading and impact-rotation drilling can be achieved at the same time, greatly increasing the rock-breaking drilling efficiency.

Bottom-hole impact-rotation stepping combined unloading rock-breaking efficient drilling system and method thereof

A high efficiency smart steering drilling system includes a smart push force application tool and a centralizer. The centralizer is at an end close to a drill bit. The smart push force application tool is at an end away from the drill bit and includes a push force application wing rib having a telescoping function. The smart push force application tool is capable of automatically measuring an inclination angle and an azimuth angle and comparing the inclination angle and the azimuth angle with design values so as to control the push force application wing rib to output a push force in a telescopic manner based on a difference between the measured values and the design values and applying a push force to the drill bit. The drilling system achieves combined deflection under double action of drill bit push and pointing, greatly improving the deflection capability.

Efficient and intelligent steering drilling system and drilling method

A drill bit performs pilot rock-breaking using an outer annular drill bit and breaks a central rock pillar using a central drill bit mounted in the middle of the annular drill bit and located inside a drill bit body to induce unloading of a bottom hole stress. A method mixes rock debris produced by rock breaking of the central drill bit as abrasive with the drilling fluid flowing into the entire drill bit as abrasive jet liquid phase to form an abrasive jet. The method includes obtaining an annular borehole by braking, and breaking the rock pillar at the inner side of the annular borehole to induce unloading of the bottom hole stress, mixing the rock debris produced by breaking the rock pillar at the inner side of the annular borehole as abrasive with the drilling fluid entering the drill bit to form an abrasive jet.

Drill bit with joint function of induced unloading and abrasive jet and drilling method thereof

The present invention discloses a drilling speed increasing device driven by a downhole motor for generating shock vibration. The device uses the rotational energy of a screw motor as power to drive a lower vibration starter to rotate. Vibration starting steel balls have the function of reducing friction in the interior. During axial reciprocating motion of the upper vibration starter, a spring matched with the upper vibration starter is periodically compressed to generate spring energy. The spring energy reacts on the lower vibration starter and a main shaft connected with a drill bit, so as to periodically provide drilling pressure for the drill bit. Periodic motion of the upper vibration starter and the spring produces periodic axial vibration on the tool.

Drilling speed increasing device driven by downhole motor for generating shock vibration

A depressurization device for downhole annulus drilling fluid includes a central shaft and a barrel body sheathed outside the central shaft, the central shaft includes a force transmission shaft and a liquid separation piston; the barrel body includes a spline barrel, an elastic element protection barrel, a connector and a depressurization barrel; the elastic element protection barrel and the connector are sheathed outside the force transmission shaft; an elastic element is arranged between the elastic element protection barrel and the force transmission shaft; the depressurization barrel is sheathed outside the liquid separation piston; a first liquid storage chamber and a second liquid storage chamber are formed; a first inlet passage and a first drain passage are formed on the connector; a second inlet passage and a second drain passage are formed on the depressurization barrel; suction valves are arranged on the first inlet passage and the second inlet passage; and, second drain valves are arranged on the first drain passage and the second drain passage. In the present application, by using the vibration of a drill string as an energy source, the pressure of downhole drilling fluid is reduced.

Depressuriz od for downhole annulus drilling fluid

A screw drill bypass valve comprising a valve body, the valve body is internally provided with a first-level valve core and a second-level valve core, a first-level spring is arranged between the first-level valve core and the second-level valve core, a second-level spring is arranged between the second-level valve core and a valve seat, and a rigidity of the second-level spring is greater than that of the first-level spring; the first-level valve core is provided with an inner bypass hole, the valve body is provided with an outer bypass hole, and the inner bypass hole is conducted with the outer bypass hole when a flowing pressure within a fluid channel of drilling fluid disappears; the second-level valve core is provided with an inner diversion hole, the valve body is provided with an outer diversion hole.

Screw drill bypass valve with large displacement diversion function

The present invention discloses a drilling speed improvement device capable of producing both hydraulic pulse and impact vibration. The device has a pressure transfer rod that is arranged at an upper end of a lower joint. A spring chamber is formed among a drill body, the pressure transfer rod and the lower joint. A spring is arranged in the spring chamber. A communicating hole is formed in the drill body. A piston is arranged at an upper end of the pressure transfer rod. A pressure bearing head is arranged at an upper end of the piston. A pressure bearing base is arranged on the inner side of an upper joint. Drill bit impact loads and drilling fluid pulse jets are modulated by the longitudinal vibration energy of a drill stem, the rock breaking efficiency of a drill bit is improved by both dynamic and static loads, and harm caused by vibration of the drill stem is reduced.

Drilling speed improvement device capable of producing both hydraulic pulse and impact vibration

A weight-on-bit self-adjusting drill bit includes a reaming bit, a WOB adjusting element, a transmission mechanism and a pilot bit and a pulsating impact generating mechanism; the pulsating impact generating mechanism includes a centralizing element, a driving element, a rotating element and a throttling element which are placed and connected successively, the centralizing element, the driving element and the rotating element are connected successively, the throttling element is in clearance fit with the rotating element, both of the centralizing element and the throttling element are respectively provided with a flow-through passage for the drilling fluid to flow through, the driving element drives the rotating element to rotate, the rotating element rotates relative to the flow-through passage on the throttling element.

Weight-on-bit self-adjusting drill bit

A system for improving a drilling speed by using drill string vibration comprises a downhole drill string vibration-reduction and supercharging device, and an ultra-high pressure bit device used for a downhole supercharger. Also disclosed is a method for improving a drilling speed by using drill string vibration. Related embodiments are also disclosed.

Growing community of inventors

Qingdao, China

Yongwang Liu