Page 55 - Air and Gas Drilling Manual

Chapter 2: Surface Equipment 2-5

Figure 2-2: Water injection pump (courtesy of Mountain Air Drilling Services).

2.2.4 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.

2.2.5 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
operated 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 correct
direction of flow. If the flow is reversed, the mechanism is forced closed by the
spring and the force of the reverse flow.

2.2.6 Gauges
Each of the compressors is equipped with independent gauges to assess its
operating performance. In addition to the compressor gauges are those placed along
the flow line. A low pressure gauge is placed downstream of the primary
compressors but upstream of the booster compressor. This gauge allows assessment
of the performance of the primaries. A high pressure gauge is placed downstream of
the booster compressor to assess the performance of the primaries and booster when
high pressure compressed air is required. Pressure gauges are also placed upstream
and downstream of the water injection pump and the solids injector. These gauges
allow assessment of the performance of these injection systems. All these gauges
must be high quality gas gauges. Most drilling rig floors are equipped with a mud