Air and Gas Drilling

In the United States, air and gas drilling techniques are used extensively in parts of the southwest in and around the San Juan Basin, in parts of the Permian Basin, in Arkansas and eastern Oklahoma, in Maryland, Virginia and parts of Tennessee. Internationally, oil and gas drilling operations are carried out with air and gas drilling techniques in parts of the Middle East, North Africa and in the Western Pacific. 

Air and natural gas are often used as a drilling fluid with no additives placed in the injected stream of compressed fluid. This type of drilling is also often referred to as dusting because great dust clouds are created around the drill rig when no formation water was present. However, modern air and gas drilling operations utilize a spray at the end of the blooey line to control the dust ejected from the well. Figure 4-185 shows a typical site plan for air drilling operations. 

The relative advantages and disadvantages of the various types of air and gas drilling operations discussed are listed as follows ... 

Surface and subsurface specialized equipment are required for air and gas drilling operations. 

Air (or Gas) Downhole Motors. Some positive displacement mud motors can be operated on unstable foam. In general, these mud motors must be low-torque, high-rotalional-speed motors. Such motors have found limited use in air and gas drilling operations where directional boreholes are required. Recently a downhole turbine motor has been developed specifically for air and gas drilling operations. This downhole pneumatic turbine motor is a high-torque, low-rotational-speed motor. 

In most air and gas drilling operations, open-hole well completions are common. This type of completion is consistent with low pore pressure and the desire to avoid formation damage. It is often used for gas wells where nitrogen foam fracturing stimulation is necessary to provide production. In oil wells drilled with natural gas as the drilling fluid, the well is often an open hole completed with a screen set on a liner hanger to control sand influx to the well. 

Lyons, W., Air and Gas Drilling Manual, Gulf Publishing Co., Houston, 1984. 

Angel, R. R., Volume Requirements for Air and Gas Drilling Gulf Publishing Co., liouston, 1988. 

William C., Lyons BG, Reuben L. et al. Air and gas drilling manual Applications for oil and gas recovery wells and geothermal fluids recovery wells. 3rd Ed. Gulf Professional Publishing 2009. 

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