The directional drill is a method of borinthatch that does not drill straight vertically down lines. Due to the advancement of survey instruments and directional drilling, the practice became more widespread in the 20th century. Before that, traditional drilling methods demanded the drilling bit and pipe, drill string, and casing, to be placed in an unidirectional line. Drilling in directional direction is becoming more frequent in many offshore locations and platforms. A sequence of planned directional shifts in the wellbore is utilized for directional drilling. Incredible engineering achievements are taking place due to technological advances over the past 100 years, in terms of angles as well as turns and distances which are now covered. Techniques like multilateral, horizontal, as well as extended reach drilling (ERD), enhanced oil recovery that significantly increases the downhole yield.
What is it that makes directional drilling important? The advantages of directional Drilling
The technique of drilling directionally offers several advantages over traditional drilling techniques.
- Multiple boreholes can be dug on the same rig using directionally drilling. This reduces surface disturbance and environmental impact.
- A wide area of the oilfield could be explored using the technology of directional drilling and, as the procedure can be carried out with one drilling rig, the expense is drastically decreased.
- The exploration of more hydrocarbon reservoirs is done through the technique of directional drilling. It also studies the oil-saturated sand, also known as shale.
- The method of drilling directionally is much quicker. It helps protect the integrity of road structures, buildings, as well as natural elements.
- It decreases the amount of groundwater that is polluted and, consequently, helps protect the ecosystem and the surroundings.
- Since it can drill under the surface of obstructions, or during ongoing activities on the site Drilling directionally increases the efficiency of site operations.
- The technique of drilling directionally is long-lasting, secure, and unaffected by weather conditions.
The working principle of directional drilling
The initial phase for directional drills is comparable to the vertical wellbores. However, when the directional driller is at the specified kickoff points the direction of travel is altered by increasing the angle of the well before beginning the construction section. Survey data can be utilized to identify the orientation of the drill bits as well as the tool face. Sensors are placed on the right path to monitor the course that the drill bore is traveling.
The technique for directional drilling manipulates different parameters like the amount of weight placed on the bit, the bottom-hole assembly geometry and rotational speed, bottom-hole stiffness the placement of the stabilizer holes diameter and angle, the characteristics of the formation, and more to get the desired trajectory, directional capabilities and efficiency of drilling.
The side forces that are acting on the bit as well as the bottom hole can be adjusted by altering the position of the stabilizers within the drilling string. This assists in enhancing, maintaining the inclination, or decreasing it which is known as holding, building, and dropping angles in the technical sense.
Directional drill applications and Types of Directional Drilling
In many drilling operations, the use of directional drilling is prevalent. The use of directional drilling significantly boosts production capacity, while keeping the highest efficiency. The below drilling services make use of directional drilling techniques
- Horizontal drilling
- Drilling on multiple sides
- Drilling straight holes
- Drilling under supervision
- Drilling into the sand-sealed zones
- Drilling to find issues
- Drilling inside the salt dome
- Drilling the relief well
- Drilling using the use of a long reach
- Drilling using a tube that is coiled
Directional Drilling Operations
Directional drillers employ various methods to direct a well toward its desired position.
Jetting component gives directional capabilities when drills through loose and non-consolidated formations. Jetting bits are cone-shaped roller bits that have a large, extended nozzle or a large nozzle and two smaller nozzles. They are characterized by the “high sides” reference offered through the large nozzles that divert the proper path by moving or rotating the string of the drill.
Beginning: This means the diverting of a good path from one direction to another. The number of KOPs that can be found in one well path is determined by the degree of complexity of the planned route.
Nudging: For the top section of holes, the nudging method is employed several wellbores are located close to each other and can cause magnetic interference which increases the chance of collision with wellbores from other areas. The most efficient route is diverted from the vertical direction to avoid the risk before being directed back to the vertical.
Whipstock operations involve the use of a wedge-shaped steel tool called a whipstock downhole that is used to change the course of the pipe mechanically. The tool is made to move the tool away from the original borehole by an angle that is slight and along the desired azimuth of the sidetrack. For open or cased holes using whipstock, the operation is carried out.
Sidetracking is the act of diverting a way away from a wellbore that is already in use. This is done to prevent a great collapse or unstable zone or even a segment of a wellbore that was previously drilled. Sidetracking is also employed to start multilateral drilling or to determine the reservoir’s vertical depth. It is also used to sidetrack wells when expectations are not met.
Geosteering: The formation assessment data is collected during drilling by using the steering method. They use sensors that provide real-time input for steering decisions in horizontal and high-angle wells, such as measurements-while-drilling (MWD) or logging-while-drilling (LWD). Modern technology allows MWD as well as LWD information to be transferred more quickly and with higher data density than they did in the past. This significantly increases the accuracy of trajectory control for wells.
