Oil & Gas Directional drilling is the science of directing a wellbore along a predetermined well trajectory to intersect a designated sub-surface target. From its early beginnings in the 1920s, when many regarded it as a “black art”, oilfield directional drilling evolved to the point where we can genuinely regard it as a science, although …
Oil & Gas Measurement While Drilling systems allow the driller to gather and transmit information from the bottom of the hole back to the surface without interrupting normal drilling operations. This information can include directional deviation data, data related to the petrophysical properties of the formations, and drilling data, such as WOB and torque (check …
The oldest surveying tool for directional drilling was known as an acid bottle. When taking a survey, the tool aligned itself with the hole’s axis, but the surface of the acid remained level. The instrument was left in this position for about 30 minutes, allowing the acid to etch a sharp line on the glass …
This article discusses gyro wellbore survey tool services available today in the oil and gas industry, beginning with basic gyroscopic theory and leading up to Rate Gyro technology. There is no attempt to compare systems or provide an expert technical description of any company’s technology. The intent is instead to provide a basic understanding of …
At specific points in the well, it is helpful to determine the overall trajectory (Check directional survey calculations excel sheet) in a single survey run (e.g., just before running casing). This is usually done by a Directional Magnetic Multi shot Survey Tool which takes a series of pictures. It also can be dropped from surface …
The magnetic single shot survey tool instrument was first used in the 1930s for measuring the inclination and direction of a well. Here we shall explain its mechanism and components. Application Single-Shot surveys, which photograph the instrument at a single position, are often used by the directional driller to track the drilling bit’s progress while …
Rotary Steerable System RSS represents an evolutionary step forward in directional drilling technology, overcoming the drawbacks of steerable motors and conventional rotary BHA types. In steerable motors, to initiate a change in the wellbore trajectory, halt the rotation in such a position that the bend in the motor points toward the new trajectory. This mode, …
A steerable downhole drilling mud motors system allows directional changes (azimuth and/or inclination) of the well without tripping pipe to change the Bottom hole Assembly BHA, hence its name. This article is one of the Directional Drilling guide articles I recommend visiting to understand other deflection tool mechanisms. It consists of a drill bit, a …
The most commonly used technique for changing the trajectory of the wellbore uses a piece of equipment known as a “bent sub,” which is used only in directional well drilling (Figure 1) with a Positive Displacement (mud) motor. What is The Bent Sub In Directional Drilling A bent sub (Drilling Subs) is a short length …
The positive displacement mud motor uses the Moineau pump principle. However, Downhole mud motors in drilling have limitations. This tool has found wide application in directional drilling and even straight-hole drilling. Drilling mud motor diagrams # 1, 2, 3 & 4 show the basic design of a positive displacement motor. This article will cover the …