SAGD is the workhorse technology for in situ oil sands production. It involves a pair of horizontal wells. To avoid plugging of the wells by sand, thousands of tiny slots are machined into each well. These slots allow fluids to pass through but filter out sand particles. Presently, these slots are machined using high-speed circular saws.
In recent years, major improvements have been realized by manufacturers of abrasive water jet cutting assemblies, particularly with respect to control and accuracy. Neak Slotting Inc. has obtained a utility patent for slotted liners made using an abrasive water jets. The benefits of the new water cut slotted liners include:
• Less steel is removed for the same net open area, resulting in higher strength. This strength feature would be used to produce stronger slotted liners with the same open area, allowing SAGDproducers to drill longer horizontal wells, from approximately 900 m to over 1,200 m. The benefit to the SAGD producer is more cost effective field development and reduced environmental impact.
• Alternatively, the higher strength could be used to increase the open area while maintaining the strength of the slotted liner. This approach will result in faster production.
• When using circular saws, 3 operations are required: cutting, de-burring and seaming. When using abrasive water jets, slots are cut in one operation from the inside to the outside. Water jets inherently produce clean slots; there is no need for de-burring. Water jets naturally results in the taper of keystone slots; there is no need for thermal seaming. Abrasive water jets are a new simpler technology that leads to higher quality. For example, because seaming is not required, the slots will be less vulnerable to stress corrosion.
• With abrasive water jets, the design of slot patterns (length, number, shape, distribution) is no longer dictated by the arrangement of saw spindles. New patterns could be designed that could maximize both liner strength and open area, therefore enabling longer wells with faster production.
Neak Slotting is an early stage Edmonton- based company which aims to commercialize the production of slotted liner manufacture using abrasive water jets in 2012. Neak is owned by Narendra Singh, an engineer who has prior experience of 25 years in the oil industry, power and electricity business and has worked in the pipeline industry in India. He has worked as an ISO 9000 auditor and with ISO 14000 requirements in pipelines operations and maintenance. He is working with NAIT in the new business incubator program to commercialize this new product. Neak has partners in the Edmonton and US oil and gas equipment and water jet cutting businesses.
Neak and its US partner are presently building the prototype production line in the United States. Once the prototype production line is optimized, slotted liner samples will be produced for testing. This is expected during the summer of 2012. The prototype production line will then be relocated to a site south of Edmonton and expanded to full scale production capacity toward the end of 2012.
The purpose of this PTAC project is to perform the comparative testing of slotted liners produced using water jets vs. using saws in order to validate performance claims. This validation is necessary for oil sands producers to be able to use the new products in their fields.