Factors Affecting Drilling Quality and Speed

1. Since the drill bit speed of compound drilling is twice that of gear II of the drilling rig, and nearly four times that of gear I, it is easy to greatly increase the ROP.

2.The high rotational speed of compound drilling is suitable for the cutting characteristics of PDC bit in shear formation.

3.Wellbore trajectory is smooth. Combining directional drilling and sliding drilling for interval change, it is easy to control the dogleg angle and ensure downhole safety.

4.The drilling tool structure is effectively simplified. During compound drilling, the drilling pressure is generally <100-120kN, and the drilling requirements can be completed with fewer or no drill collars, and the sticking probability is greatly reduced.

5. The high-efficiency PDC drill bit cooperates with the power drilling tool to drill wells, which avoids the early failure of the cone bearing at high speed and does not cause cone loss accidents.

Influence of Drilling Parameters on Drilling Quality Speed

During the drilling process, the influence of the drilling parameters among the controllable factors on the drilling speed cannot be ignored, such as: bit type, bit nozzle diameter, bit water power, bit pressure, speed, pump pressure, displacement, etc. In the case of certain objective conditions, the ROP is usually increased by controlling the drilling pressure, rotational speed, pump pressure and displacement.

Influence of Drilling Fluid on Drilling Quality and Speed

Drilling fluid is the blood of drilling, so the performance of drilling fluid is very important to drilling. The main factors affecting the ROP are the viscosity of the drilling fluid, the density of the drilling fluid and the solid content in the drilling fluid. In view of the fact that the treatment agent used in the existing deep well fluid system is rich in chromium ions and other heavy metal ions that have a great impact on the environment, it is recommended to study and apply an environmentally friendly deep well drilling fluid system to improve the silicate drilling fluid system currently used in a small range in China , Synthetic basic drilling system to form a deep well environmental protection drilling fluid series suitable for the geological and engineering conditions of each drilling area.