Word of the Week – Casing Shoe

Casing Shoe

In geothermal wells, this is the bottom of the cemented casing string. Below the casing shoe, the well may be unprotected and open to the surrounding rock or lined with a slotted liner. The depth of the casing shoe generally coincides with the top of the production interval in the reservoir.

Did you know… one of the world’s largest hot springs is in New Zealand?

Did you know... one of the world’s largest hot springs is in New Zealand?

Located in the Waimangu Volcanic Rift Valley near Rotorua, Frying Pan Lake is one of the world’s largest hot springs! It is also one of the youngest, with a precise birthdate of April 3, 1917, having filled and formed in the aftermath of a hydrothermal eruption that lasted three days.

The origin of the lake dates to the early morning hours of  June 10, 1886, when Mount Tarawera came to life. This is New Zealand’s deadliest volcanic eruption, even if it was small in size and lasted just a few hours. A line of craters 16 km (~10 mi) long was the result. One, Echo Crater, which hosts Frying Pan Lake, was transformed in the years that followed into a flat-bottomed basin by the erosion-sedimentation of loose ash that blanketed the surrounding hillsides. Because of the steam vents that dotted the basin floor, it became known as Frying Pan Flat.

The hot lake covers an area of 38,000 m2 (~409,030 ft2) and reaches 15 m (45 ft) depth. Swirls of steam rise off the lake surface owing to the inflow of boiling water from four underwater vents. Hot water (50-60˚C; 122-140˚F) overflows the east side of the lake at up to 2000 gallons/minute.

Frying Pan Lake hosts a variety of thermophile organisms, including cyanobacteria and the single-celled archaea. These represent some of the earliest forms of life, making it a modern laboratory for field study of evolution in extreme conditions.

Waimangu is open to tourists. A self-guided nature walk takes one around the edge of Frying Pan Lake. Other amazing sights include the aqua-colored and hot Inferno crater lake, spouting hot springs, silica stalagtites, and Lake Rotomahana, which was the site of the famous Pink and White silica terraces.





Word of the Week – MWD


Refers to Measurement While Drilling which for directional drilling includes geospatial information that is used to steer the bottom hole assembly (BHA). Inclination and azimuth are surveyed using accelerometers and magnetometers which are incorporated into MWD tools. Other MWD information includes rotational speed of the drill string, type and severity of downhole vibration, temperature, and torque and weight on bit.

Word of the Week – BHA


Refers to Bottom Hole Assembly, which is the system of tools at the bottom of the drill string that is used for drilling directional wells. The BHA includes the drill bit, mud motor, drill collar, and any tools that are used for making measurements while drilling.

Word of the Week –

Heat exchanger

A device or engineered system that is used to transfer thermal energy in soil, rock or produced fluid to heat a closed loop through which another fluid is circulated. Heat exchangers are used in ground sourced heat pumps, binary plants, and a range of direct use applications.