Rarefied Air: Drilling for Helium in North America

Helium is one of the most abundant in advanced medical technologies such as MRIs, and in cryogenics, aerospace applications, and microchip manufacturing. It is also used to fill party balloons. It’s essential, expensive, and supplies are running low. Helium is about 100 million times more abundant in one place—but that place is on the moon. While trace amounts can even be found in the very air we breathe, the gas is difficult to find in commercial quantities, and those quantities are usually found as a byproduct of natural gas discoveries. Historically, about 40% of the US supply of helium came from the Federal Helium Reserve, a US Bureau of Land Management (BLM)-operated storage reservoir, enrichment plant, and pipeline system near Amarillo, Texas. The reserve was set up in 1960 as a strategic repository so that BLM could supply crude helium to private helium refining companies, which in turn refined it and marketed it to consumers. In the mid-1990s, Congress passed a bill to sell off a large part of the reserve’s supply to help pay off the facility’s debt, and effectively set in motion the federal government’s exit from the helium business. In 2013, BLM said it would begin auctioning off an increased percentage of the reserve annually as part of the bill. Last year, BLM announced the closure of the reserve. At the time of the announcement, BLM Deputy Director for Policy and Programs William Perry Pendley said “now it is time for the US government to remove itself from the helium business and allow the private sector to further develop this industry to meet the supply needs of the United States, creating a sustainable economic model and jobs for Americans.” BLM held its final crude helium auction in 2019, with the price rising 135%, from $119/Mcf a year earlier to $280/Mcf. Market pricing for helium is difficult to know. It is not a traded commodity, and pricing is normally based on long-term, confidential contracts. It’s a niche market that suffers from a lack of detailed analysis due in large part to the availability of its closely held data. The helium industry shares many aspects of the oil and gas business. Commercial deposits are found via geological survey; then, once identified, drilling begins. Outside of the search and discovery, helium can also be a useful tool for those in the oil business. It can be used for leak detection and in specialized welding due to its inert properties and high heat transfer. Additionally, as the oil field moves more toward digitalization, storage of big data will need helium for the construction of storage drives and to keep server farms cool. Swapping Hydrocarbons for Helium As scientific developments advance, the need for helium increases—a notion not lost on Canada-based Avanti Energy. The company’s CEO Chris Bakker has more than 2 decades of experience in oil and gas, most recently working as a commercial negotiator with Encana/Ovintiv for major facilities and pipelines in the Montney gas play. Today, he and his team are looking for commercial helium deposits in southern Alberta and northern Montana.

Evaluation of deep geothermal exploration drillings in the crystalline basement of the Fennoscandian Shield Border Zone in south Sweden

The 3.1- and 3.7-km-deep FFC-1 and DGE-1 geothermal explorations wells drilled into the Precambrian crystalline basement on the southern margin of the Fennoscandian Shield are evaluated regarding experiences from drilling, geological conditions, and thermal properties. Both wells penetrate an approximately 2-km-thick succession of sedimentary strata before entering the crystalline basement, dominated by orthogneiss, metabasite and amphibolite of the (1.1–0.9 Ga) Eastern Interior Sveconorwegian Province. The upper c. 400 m of the basement is in FFC-1 severely fractured and water-bearing which disqualified the use of percussion air drilling and conventional rotary drilling was, therefore, performed for the rest of the borehole. The evaluation of the rotary drillings in FFC-1 and DGE-1 showed that the average bit life was very similar, 62 m and 68 m, respectively. Similarly, the average ROP varied between 2 and 4 m/h without any preferences regarding bit-type (PDC or TCI) or geology. A bottomhole temperature of 84.1 °C was measured in FFC-1 borehole with gradients varying between 17.4 and 23.5 °C/km for the main part of the borehole. The calculated heat flow varies between 51 and 66 mW/m2 and the average heat production is 3.0 µW/m3. The basement in FFC-1 is, overall, depleted in uranium and thorium in comparison to DGE-1 where the heat productivity is overall higher with an average of 5.8 µW/m3. The spatial distribution of fractures was successfully mapped using borehole imaging logs in FFC-1 and shows a dominance of N–S oriented open fractures, a fracture frequency varying between 0.85 and 2.49 frac/m and a fracture volumetric density between 1.68 and 3.39 m2/m3. The evaluation of the two boreholes provides insight and new empirical data on the thermal properties and fracturing of the concealed crystalline basement in the Fennoscandian Shield Border Zone that, previously, had only been assessed by assumptions and modelling. The outcome of the drilling operation has also provided insight regarding the drilling performance in the basement and statistical data on various drill bits used. The knowledge gained is important in feasibility studies of deep geothermal projects in the crystalline basement in south Sweden.

Evaluation of Deep Geothermal Exploration Drillings in the Crystalline Basement of the Fennoscandian Shield Border Zone in South Sweden.

The 3.1 and 3.7 km deep FFC-1 and DGE-1 geothermal explorations wells drilled into the Precambrian crystalline basement on the southern margin of the Fennoscandian Shield are evaluated regarding experiences from drilling, geological conditions, and thermal properties. Both wells penetrate an approximately two-kilometre-thick succession of sedimentary strata before entering the crystalline basement, of granitoid gneiss, metabasite and amphibolite of the (1.1–0.9 Ga) Eastern Interior Sveconorwegian Province. The upper c. 400 m of the basement is in FFC-1 severely fractured and water-bearing which disqualified the use of percussion air drilling and conventional rotary drilling was therefore performed for the rest of the borehole. The evaluation of the rotary drillings in FFC-1 and DGE-1 gave that the average bit life was very similar, 62 m respectively 68 m as well as an average ROP between 2 and 4 m/h without any preferences regarding bit-type (PDC or TCI) or geology. A bottomhole temperature of 84.1 °C in FFC-1 borehole with gradients varying between 17.4 °C/km and 23.5 °C/km for the main part of the borehole. The calculated heat flow varies between 51 and 66 mW/m2 and the average heat production is 3.0 µW/m3. The basement is in FFC-1 overall depleted of uranium and thorium in comparison to DGE-1 where the heat productivity is overall higher with an average of 5.8 µW/m3. The spatial distribution of fractures was successfully mapped using borehole imaging logs in FFC-1 and shows a dominance of N–S oriented open fractures, a fracture frequency varying between 0.85 and 2.49 frac/m and a fracture volumetric density between 1.68 and 3.39 m2/m3. The evaluation of the two boreholes provides insight and new empirical data on the thermal properties and fracturing of the concealed crystalline basement in the Fennoscandian Shield Border Zone that previously only been assessed by assumptions and modelling. The outcome of the drilling operation has also provided insight regarding the drilling performance of the basement and statistical data on various drill bits used. Properties and experiences which are all important in feasibility studies of deep geothermal project in the crystalline basement in south Sweden.

Construction technology and parameter calculation of air drilling with raise boring machine

Based on the characteristics of raise boring technology and air drilling technology, the construction equipment and process of raise boring with air as circulating medium are studied. Raise air drilling equipment includes the hydraulic control system, the air-cooled cooler and the air compressor. The drilling process is that the bit is cooled by the high-pressure air, at the same time, the broken rock debris generated in the drilling process are discharged to the ground, and the high temperature hydraulic oil is cooled by the air-cooler cooler. By the study above, the problems are solved effectively such as heat dissipation, cooling and rock debris collection and discharge in the process of construction with raise boring machines without drilling fluids. Based on the basic assumption and the aerodynamic theory, the circulation system pressure of the raise air drilling is studied, the calculation method and formula of the annular pressure drop, bit pressure drop and rod pressure drop are presented. The research results can provide theoretical guidance and technical support for the application of raise air drilling technology.

Selection and application of the minimum gas injection volume of air drilling with raise boring machine

Gas injection volume is the key parameter of air drilling with raise boring machine, and the determination of the minimum gas injection volume is one of the key technologies to improve the drilling speed and shorten the drilling period. Based on the characteristics of raise boring technology, the construction technique of raise boring with air as circulating medium is studied, and the double-channel structural characteristics of direct circulation system are discussed. On the basis of summarizing and analyzing the principle and characteristics of the calculation methods, the minimum gas injection volume required for rock carrying in the engineering of air drilling with raise boring machine is calculated by using the minimum velocity method. The research results provide a basis for the design of drilling parameters and are of great significance for expanding the application range of raise boring method and realizing the safe and rapid construction of shaft.

Experimental Investigation of Force Response, Efficiency, and Wear Behaviors of Polycrystalline Diamond Rock Cutters

Polycrystalline diamond compact (PDC) cutters are the most extensively used tool for rock drilling in superdeep oil and gas exploration, in which the air drilling technology without drilling fluid is highly promoted. This study examined the performance of PDC cutters in air drilling, including their friction angle, cutting force, specific energy, and wear behaviors, using a home-made testing apparatus and a commercial tribometer. It also investigated the dependence of cutting force on cutting depth and back rake angle. Results obtained in both dry conditions and in drilling fluid media were compared, and a tentative explanation to the observed differences was brought about by these two environments.