Southwest Petroleum University

Hao Yu

Tiejun Lin

Jianfeng Liu

Gao Li

Xiangchao Shi

Qiang Zhang

Yuming Wang

Taihe Shi

Chengxiu Yu

Xin Zeng

Chengsong Yang

Zelin Zhu

Jianhua Guo

Ying Zhang

Leiyu Gao

Ruiqi Shen

Hao Han

Jiachang Nie

Zeqian Ren

Xiuping Chen

Yuheng Tuo

Wenle Yu

Yuting Dai

Zhanghua Lian

Shuanggui Li

Yong He

Qingling Li

Provided is a novel wear-resistant and collision-resistant polycrystalline diamond compact (PDC) drill bit with rostriform teeth and a plurality of blades, including an upper joint and a drill matrix. The PDC drill bit with rostriform teeth and a plurality of blades breaks rocks jointly by the primary teeth by way of penetration-splitting and the secondary teeth by way of shearing, so that the torque needed to break the rocks is greatly reduced. The design of the plurality of blades balances force distribution between rocks and blades at a shaft bottom, so that the abrasion loss of the teeth within a unit time is reduced. The present invention solves the technical problems in the prior art that cutting positions are abraded, and the teeth are fed slowly and are unreasonably distributed.

Wear-resistant and collision-resistant polycrystalline diamond compact (PDC) drill bit with rostriform teeth and plurality of blades

The present disclosure discloses a method for calculating a safe drilling fluid density in a fractured formation, including the following steps: S, performing image processing to identify a downhole fracture; S, establishing three-dimensional (3D) geological models based on parameters of the downhole fracture, and establishing a drilling wellbore model based on a size and length of a wellbore; S, assigning the model with material parameters, boundary conditions, and upper and lower bounds of an initial drilling fluid density, and calculating accuracy; S, solving the 3D geological models using a 3-dimension distinct element code (3DEC) and determining stability of a well wall; S, determining upper and lower bounds of a drilling fluid density using dichotomy; S, repeating steps Sto S; and S, after set accuracy conditions are reached, saving and outputting the safe drilling fluid density.

Method for calculating safe drilling fluid density in fractured formation

A remote-controlled adjustable-speed screw drill for gas-drive hydraulic-motive during gas drilling is provided, including a piston speed control system, a motor assembly, a cardan shaft assembly and a transmission shaft assembly which are connected with each other from up to down in sequence. The motor assembly includes air inlets, a cam, air cylinders, pistons, a connecting rod, air outlets, liquid inlets, hydraulic cylinders, liquid check valves, a liquid storage chamber, liquid outlets, a liquid injecting chamber, a liquid injecting hole, an anti-drop cap, a rotor, a stator, and a motor assembly housing. The present invention utilizes the high-pressure gas injected by the gas drilling to drive the pistons to move back and forth at high-speed, so as to drive the incompressible liquid within the driving screw to achieve the self-circulating motion, and the screw rotor is driven to rotate by the liquid.

Remote-controlled adjustable-speed screw drill for gas-drive hydraulic-motive during gas drilling

Growing community of inventors

Sichuan, China

Hao Yu