|“Nanite” for Better Well-Bore Integrity and Zonal Isolation
||Last Reviewed 6/19/2014
The project goal is to demonstrate how real-time sensing of Nanite™ can improve long-term wellbore integrity and zonal isolation in shale gas and applicable oil and gas operations. Nanite is a cementitious material that contains a proprietary formulation of functionalized nanomaterial’s additive to transform conventional cement into a smart material responsive to pressure (or stress), temperature, and any intrinsic changes in composition. Nanite’s electrical, radiometric, and acoustic properties; improved chemical and physical properties; and durability have the potential to ensure long-term wellbore integrity and zonal isolation.
Oceanit, Honolulu, Hawaii 96813
Well integrity and performance failures occur for different reasons, one of which is poor cementing. Cementing is a crucial step in drilling safely for oil or natural gas; however, it is an inherently uncertain process and prone to frequent failures such as the one that led to the Deepwater Horizon disaster in the Gulf of Mexico. Environmental protection regulations generally require that cement extend to 150 ft. below the deepest water well in the area in order to protect aquifers from wellbore fluids. Thus the fracturing process is not supposed to begin until the wellbore has been properly cased and cemented. However, contractors often rush the casing and cementing process and what may at first appear to be a good cement job or casing connection ends up being degraded by the pressure exerted during the fracking process, which causes the casing to fail at the connecting joints or cement cracks. The cracked cement or failed casing then allows wellbore fluids (including fracking fluids and natural gas) to contaminate aquifers or the surface.
Conventional techniques (such as acoustic and ultrasonic) used by industry to inspect the integrity of cementing behind multiple casing strings have proven to be inaccurate, insufficient, and unreliable, and continuously monitoring the integrity of cement plugs throughout their lifetime using conventional approaches is not a viable option. Hence, there is imminent need for new cement evaluation technologies and approaches to improve the effectiveness of existing technologies to assess cement integrity. Oceanit’s Nanite will be tailored to address key challenges faced during oil and gas cementing.
The cementing process was developed well over a century ago and the cementing material currently being used has not undergone any significant improvement or innovation since that time. The proposed research utilizes nanotechnology to address persistent cementing issues such as wellbore integrity and zonal isolation. A smart, sensing, durable cementing material such as Nanite™ will significantly improve the economics of drilling by helping to prevent blowouts and resolve environmental concerns.
Accomplishments (most recent listed first)
- Evaluated Nanite cement electrical impedance response to dynamic mechanical loading
- Refined lab-scale electrical impedance interrogation technique for Nanite
- Assessed properties of Nanite slurries and cements according to API specifications and found the impact of Nanite admixtures on cement properties to be minimal
- Nanomaterials were qualified for initial vendor selection via chemical, thermal, and microscopic analysis
- Early stage technology demonstration of Nanite at the Houston Technology Center in conjunction with the Offshore Technology Conference with over 60 oil and gas industry leaders attending
- Joint Industrial Partnership formed with four major oil and gas operating companies
Current Status (June 2014)
Oceanit optimized the electrode configuration at lab scale in order to provide reliable, repeatable, and accurate detection of cement condition. They also investigated the effects of curing and mechanical loading on the electrical impedance spectra of Nanite cement and found good correlation. Oceanit will continue to develop their electrical interrogation technique for Nanite as well as explore additional modes of stimulation and detection, including magnetic, acoustic, and radiometric.
Project Start: October 1, 2013
Project End: September 30, 2016
DOE Contribution: $1,132,074
Performer Contribution: $300,000
NETL – William Fincham (firstname.lastname@example.org or 304-285-4268)
Oceanit – Vinod Veedu (veedu@OCEANIT.COM or (713) 357-9622)