Thixotropic cement slurry in oil and gas is a system that has the capability to develop a self-supporting gel structure. This structure carries part of the hydrostatic pressure of the cement column, thereby reducing the pressure against the formation. This is significant in a low gradient situation where heavy fluid losses would otherwise be experienced …
We define annular pressure loss or APL as the pressure lost while circulating drilling mud in the annulus. This loss is mainly due to frictional forces between the mud, borehole wall, and drill string. What Is The Pressure Loss? Pressure is required to circulate mud around a wellbore. This pressure is necessary to overcome the …
After successfully perforating using wireline guns, experts proposed that they could run similar guns on pipes. This allowed for longer sections of the gun to be utilized, reducing the rig time required for well completion. Further time savings could be achieved by combining the guns with the completion string. In the 1930s, Halliburton patented the …
If you’re involved in drilling operations, you know how important it is to understand the concept of “bottom hole pressure.” This term is critical for drilling supervisors, drillers, drilling engineers, and all rig personnel, as it directly impacts well control. In fact, if the BHP drops below the formation pressure, it can cause a kick …
Hard formation drilling presents significant challenges to Polycrystalline Diamond Compact PDC bits. The major cause of reduced ROP and bit life has been identified as lateral downhole drill string vibration or ‘bit whirl’. The phenomenon manifests itself in the form of high irregular torques and poor rates of penetration. The negative impact of vibrations on …
The Drilling BHA is a very slender structure with a length-to-width ratio exceeding 500. Buckling will occur at high WOB. The buckling of the BHA string hurts overall drilling performance. It induces extra friction, leads to additional loading of components, and can induce violent dynamic behavior in the BHA, which can cause tool or drill …
The original version of the Drilling Calculations Data Handbook PDF was first distributed in 1950. Since then, there have been eight additional releases, including numerous new advancements and equipment. However, the main objective of the handbook has always been to remain user-friendly and accessible. Its philosophy has consistently provided quick access to essential information and …
The length of the annulus or the length of the low-density fluid and mud density of the lost circulation can be calculated based on the annulus capacity behind the drill collar. Suppose the lost circulation volume is smaller than the annulus volume against the drill pipe. In that case, the length of the annulus (i.e., …
Keyseating is one of the primary reasons for fishing during drilling. A key seat is a small hole cut into the well bore wall due to the movement of the downhole drilling assembly. This cut usually happens when the hole changes direction, the hump of doglegs, in undetected ledges near washouts. A part of the …
In the drilling industry, the rate of penetration (ROP), also known as penetration rate or drill rate, is the speed at which a drilling bit breaks the rock under it to deepen the borehole. It is generally measured in feet per minute or meters per hour. Generally, ROP increases in fast-drilling formations such as sandstone …