Page 48 - Air and gas Drilling Field Guide 3rd Edition

3.2 Flow Line to the Rig 39

FIGURE 3-2. Water injection pump (courtesy of Mountain Air Drilling Services).

operations are carried out without some water, chemical additives, and foam pro-
ducing additives being injected.

3.2.4 Solids Injector
The solids injector is used to inject hole drying and hole stabilizing powders into
the well to dry water seeping into the well from water-bearing rock formations.
Other solids are often injected to reduce torque between the drill string and
the borehole. These torque reduction solids are often necessary when drilling
highly deviated and horizontal boreholes.

3.2.5 Valves
Both manually and remotely operated valves are located along the flow line to the
rig. These valves are usually the gate or ball type. These valves cannot be oper-
ated in a partially open position. The abrasive nature of the compressed air flow
in the flow line would erode the gate or ball of the valve and render the valve
ineffective in the closed position. At strategic locations along the flow line are
check valves. These special mechanical valves allow compressed air flow in only
one direction (toward the standpipe). These check valves are spring loaded and
the force of the flow allows the mechanism (flapper-gate or ball) to open in the
correct direction of flow. If the flow is reversed, the mechanism is forced closed
by the spring and the force of the reverse flow.

3.2.6 Gauges
Each of the compressors is equipped with independent gauges to assess its
operating performance. In addition to the compressor gauges are those placed