Horizontal Directional Drilling Industry in the Oil and Gas fields
The uncelebrated horizontal directional drilling industry increases well productivity, prolongs the reservoir’s commercial life and eliminates water or gas intrusion into the product.
On January 28, 2015, David Blackmon reported in Forbes magazine, “Horizontal drilling [is] a technological marvel ignored. The massive new shale, gas and oil resources discovered in recent years were made possible by horizontal drilling.”
Horizontal drilling is far more sophisticated than the frac-stimulation of existing oil wells practiced during the late 1980s. Simple frac-stimulation techniques fractured rock to allow trapped oil or gas to flow into the well. Sand blasting at high pressure kept the fractures open, but sometimes dislodged rock particles damaged drilling equipment.
It is now possible to drill horizontally into a 100 foot thick rock formation containing hydrocarbons. Traditional vertical drilling accessed only 100 feet of rock. Horizontal drilling allows the operators to drill a mile horizontally through rock formations.
Innovative horizontal drilling allows a driller to bore a hole, 10,000 feet deep, with a mile long extension at a right angle to the vertical shaft and insert the drill bit directly into natural gas or oil reservoir. Sensors and actuators located directly above the drill bit measure and act on temperature, pressure, fluid content, depth, length or GPS readings. The same actuators collect samples of rock or fluid at measured depths or distances on the horizontal extension.
Oil and gas reservoirs are located regionally or extended by hydrocarbon surveys. Light signatures emanating from the earth detected by sensors on orbiting satellites are used to map and interpret the composition of solids and gases. Methane gas is easily identifiable. Hydro- carbon mapping adds detailed readings of temperature, radio waves, ionization and geomagnetic force to satellite images to locate oil and gas reservoirs within a 1000-acre range.
Deciding where to drill depends on thickness, depth and shape of heterogeneous or homogeneous rock layers, land rights, existing infrastructure of roads and highways and government regulations. Vibrations sent from a large truck measure distance and strength of vibrations to create seismic studies of the rock layers. Drilling equipment and pipes must be transported to the site, and the oil or gas has to reach customers when the well is completed. Contracts with landowners, government permits, compliance with the Department of Environmental Protection and the well site must be registered.
One horizontal well reaches more energy than ten vertical wells. When drilling a horizontal well, the driller must calculate the depth of the gas or oil reservoir and analyze rock samples from beneath the earth’s surface. A drill bit assembly, loaded with sensors, tracks its vertical and horizontal coordinates. The drill bit turns incrementally until it is horizontal, this point is labeled the “kickoff point” and continues to the “entry point” where it reaches oil or gas until oil or gas flows freely from the well.
Robert King, author of a report on “the cutting-edge upstream oil and gas industry technology, horizontal drilling,” to the Energy Information Administration of the United States Department of Energy portrayed “the technological development and deployment” of the horizontal drilling industry. Horizontal drilling was considered in Pennsylvania during 1944, but it did not become a feasible option until sensors and actuators improved equipment and motors.
Physically, horizontal directional drilling is short, medium or long radius and employ the same rotary drills used to drill vertical wells. The entire drill assembly rotates and is attached to joined steel alloy pipes. The pipes must be flexible enough to bend and sturdy enough to prevent collapse a mile below the earth’s surface.
A fluid-driven hydraulic motor or a turbine motor drives the drill bit from a position beneath the ground directly above the drill bit. Heavy drill collars exert downward force on the drill bit. Coiled tubing may be used in lieu of pipes.
Well logs of continuous records of depth, length, types of rock penetrated and their fluid content are maintained. Chemical introduction of 10 or 15 percent hydrochloric acid dissolves salt in rock opening fractures to release oil or natural gas. Closed fracture acidizing etches natural fractures simplifying the drilling process. Finished wells are usually cased with thin wall tubing and cemented. Cement is pumped down into the well between the casing and the well wall. Casing prevents water from entering the well.
The cost of horizontal drilling has decreased 283% since 1991 and the financial benefits justify the expense. The aggregate surface area required, the intrusion on the landscape, is reduced by horizontal oil and gas wells. Horizontal directional drilling reduces production problems, decreases low efficiency and decreases premature abandonment of the well.
The horizontal directional drilling industry employs geologists, scientists, engineers, well drillers, management professionals, sales people, mechanics and truck drivers internationally. Horizontal directional drilling professionals work in oil and gas companies, economic development agencies, law offices and government agencies in all of the contiguous United States.
The horizontal directional drilling exponentially increases profit, royalty payments to land owners and tax revenue paid to the local governments. A productive horizontal well reduces the need for multiple vertical wells and the consumption of water. The horizontal directional drilling industry increases returns to landowners and returns higher royalties to mineral owners. Huge tax revenues from horizontal directional drilling benefit local and state departments of revenue.
Thanks to Horizontal Directional Drilling Technology – horizontal wells release fewer toxic emissions; they reduce air pollution, provide abundant natural gas, burn cleaner and reduce greenhouse gas emissions to pre-1990 level.