Parratt Wolff Inc

A window into the earth. That is a very good description of each borehole we drill! These windows are sometimes a 300’ deep boring in coastal sediments - other times a 100’ angle core hole in karst. As these windows are drilled, samples of overburden or rock can be collected using a wide variety of tooling, all operated by our professional crews.

The following drilling and sampling
methods are available:

Geoprobe ® direct push

Hollow stem auger

Fluid rotary 3” to 12” O.D.

Flush joint steel casing 2 1/2” I.D. to 8” I.D.

Diamond coring

Air hammer drilling 4” O.D. to 8” O.D.

Split spoon sampling, continuous samplers, Shelby tube sampling

Auger Drilling

Hollow stem augers are the industry standard for environmental drilling. An auger bit is an excellent tool for penetrating most overburden formations while the helical flights on each auger section elevate the cuttings to the ground surface. Their “hollow” construction permits the installation of various types of soil or groundwater samplers to be driven ahead of the auger bit for sample collection. The following are typical diameters of the augers run by PWI.

Inside diameter
3 1/4”
4 1/4”
6 1/4”
8 1/4”
10 1/4”
Nominal outside diameter
6”
8”
10”
12”
14”

Diamond coring

Diamond coring is an excellent method for collecting high-quality samples of consolidated formations. Parratt-Wolff uses two common coring systems, wireline and conventional. With wireline coring, the core barrel is left in place between each run along with the drill rods. Only the inner core barrel containing the rock sample is removed using a winch cable. Wireline coring is a very fast method for coring and excellent on:

sites with a ready supply of water for drilling

when drilling in highly fractured formations, and

drilling holes deeper than 30’ or with more than 20’ of rock core.

By contrast, a conventional coring system requires that the entire core barrel and all of the drill rods be removed between each run. This process can be very time consuming as a borehole is advanced deeper and deeper into bedrock.

Common core sizes run by Parratt-Wolff

Type

NQ
NX
HQ
HX
PQ
PX
Type of system

Wireline
Conventional
Wireline
Conventional
Wireline
Conventional
Hole diameter

2.98”
2.98”
3.78”
3.78”
4.83”
4.83”
Core size

1.88”
1.88”
2.50”
2.50”
3.35”
3.35”