Common Drilling Methods For Oil and Gas Extraction
The worldwide measurement of the drilling market was worth more than USD 11.9 billion in 2019. According to predictions, this is expected to increase at a compound annual growth rate (CAGR) of 7.8 percent by 2027, owing to the advancement in oil drilling technologies. Today, offshore well intervention companies like PRT Offshore and many others are helping investors navigate the industry smoothly and are committed to leadership at their facilities and on drilling locations.
Common Oil and Gas Drilling Methods
Below are some methods used today to extract oil and gas from the Earth:
1. Percussion (Cable Drilling)
Percussion drilling is a manual method that involves lowering a heavy cutting or hammering a bit tied to a rope or cable into an open hole or within a temporary casing. The approach is also known as the ‘Cable tool.’ A tripod is often used to support the tools.
The cutting or hammering bit loosens the soil or cemented rock in the borehole by pushing the rope or cable up and down, which is subsequently removed later using a bailer.
This drilling method is ideal for unconsolidated and consolidated formations such as sand, silt, sandstone, and even gravel. Manual percussion can penetrate to depths of around 25 meters.
Rotary tables, winches, and other similar devices are powered by electric motors in this method, resulting in more operational flexibility and remote-controlled drilling. In addition, these drills are novel ways of oil and gas exploration because they provide more power to the drill.
The electro-drilling technology has shown to be effective in difficult geological settings where weighted mud or mud mixes are used. These locations include Turkmenistan, Ukraine, and Azerbaijan.
3. Rotary Drilling
Rotary drilling digs into the Earth’s crust using a sharp, revolving drill bit. The spinning of the drill bit, similar to that of a standard hand-held drill, enables penetration of even the hardest rock.
The use of a rotating drill bit is not a new thing. Archeological evidence suggests that the Egyptians may have used a comparable method as early as 3000 B.C.
The penetration rate is quicker when employing air-based drilling fluids instead of water-based ones. In this circumstance, a drag bit is excellent for penetrating unconsolidated sediments, but a roller bit can drill through consolidated rock.
4. Dual-Wall Reverse-Circulation Drilling
When selecting a drilling technique, particularly for exploration and grade control, numerous variables must be considered, including cost, duration, environmental effect, depth of drilling, and sample quality. Reverse Circulation drilling has many benefits over other drilling processes, such as Rotary Air Blast or diamond drilling.
This technique is suitable for all kinds of geologic formations and does not need surface casing.
One of the method’s key features is its ability to retrieve samples. In addition, the approach enables rapid penetration in alluvial or fissured rock. It also aids in generating an accurate assessment of aquifer production from formation depths.
5. Directional Drilling
Directional drilling is an extension of the rotary drilling method, in which the drill is guided along a curved route as the hole is deepened.
Oil explorers may use directional drilling to access resources that vertical drilling cannot reach. The ability to drill several wells in all directions on a single platform reduces costs significantly. This also enables access to underwater reservoirs.