Whether it’s water, oil or natural gas, drilling straight down into the earth has traditionally been the best way to go about extracting resources. However, the direction of a wellbore can be changed in a number of ways, and so-called “directional drilling” is today a common alternative to vertical wells.
Drillers often prefer directional drilling in shale reservoirs because it is sometimes the best way to access the most productive reservoir rock. Targets that can’t be reached by vertical drilling (under a residential area, for example) can be using directional drilling.
Vertical wells might be better for highly permeable rock, where hydrocarbons can flow over long distances and reach the wellbore. But where permeability is low (and fluids move slowly), directional drilling can boost production by bringing the bore ever-closer to the source.
Altering the direction of a wellbore through one of the following methods:
- Whipstocks. Curved steel wedges used to “branch off” the borehole direction;
- Different bottom hole assembly (BHA) configurations. The BHA is the part of the drill string that affects the trajectory of the wellbore. Special BHA components and drill bits such as rotary steerable tools allow steering while rotating, usually with higher rates of penetration and ultimately smoother boreholes;
- Mud motors. Positive displacement motors that use “drilling mud” (drilling fluid) to drive the drill bit. These long cylinders extend the drill string; with a drill bit on one end, they consist of a power section, transmission and output shaft assembly.
The Role of Polyurethane Components
Polyurethanes are a class of polymers that can be tailored for use in a large number of applications. They can be thermoset or thermoplastic, rigid or hard, flexible or soft. It’s no surprise that polyurethane components support horizontal drilling operations as much as other oil and gas activity. Durable and reliable, they provide material handling at the surface and material stability downhole.
High-pressure/high-temperature downhole operating environments require high-performance seals, bearings and connectors. In fact, some of the most critical downhole components are the polyurethane sealing elements. Above ground, polyurethane rollers make it possible to move the pipe from the truck to the wellhead.
Corrosion-resistant and compression-resistant directional drilling equipment that may incorporate polymer/polyurethane components also include:
- Drilling jars and hammers
- Reamers and hole openers
- Drilling motors and bits
- Tubing hangers
- Casing hangers
- Chemical injection systems
- Sub-surface valves
- Artificial lift systems (ALS)
- Liner hanger systems
The oil and gas industry demands a lot of its equipment and tools, and polyurethane is capable of taking any punishment that is thrown at it. Polyurethane’s versatility is second to none. It can be molded into rollers, tubes, bushings, nozzles, scrapers, clamps, seals, gears and pads—with whatever customizations are needed. As a spray coating, foam, flexible elastomer or rock-hard component as tough as steel, polyurethane covers all the bases.