|“Nanite” for Better Well-Bore Integrity and Zonal Isolation
||Last Reviewed 6/29/2015
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 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 resolving environmental concerns.
Accomplishments (most recent listed first)
- Received Budget Period II continuation authorization.
- Hosted DOE program manager site visit in May 2015.
- Demonstration of pipe expansion test with impedance logging.
- Development of high bandwidth impedance analyzer electronics.
- Acoustic transmission loss comparison between Nanite and base cement.
- Optimization of electrical impedance of electrode materials used for Nanite measurements.
- Evaluated Nanite electrical impedance humidity dependence.
- Refined lab-scale electrical impedance interrogation technique for Nanite.
- Nanite electrical impedance measurements transitioned to concentric casing form factor.
- A novel hybrid acoustic-electrical technique for monitoring Nanite is being developed.
- A Nanite curing model was developed to predict hydration rate and level based on electrical impedance measurements.
- Electrical impedance measurements have been used to reliably detect dynamic mechanical loading and fracture of Nanite.
- A next generation Nanite electrical impedance analyzer module with small form factor and low energy requirement was designed, produced, and calibrated.
- Preliminary acoustic characterization of Nanite has revealed distinguishing acoustic properties.
- 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.
- Dissemination of results to communities of interest:
- Oceanit attended the TechConnect World Innovation Conference and Expo 2014. TechConnect World is the world’s largest multi-disciplinary multi-sector conference and marketplace of vetted innovations, innovators and technology business developers, and funders. Oceanit presented on advanced materials and exhibited its latest innovations, including Nanite, in its exhibition booth.
- Dr. Vinod Veedu delivered the keynote presentation at the International Association of Drilling Contractors Advanced Rig Technology Conference and Exhibition in Galveston, TX on September 16, 2014. The event was an opportunity to explore potential applications of Nanite for well cementing and showcase recent developments. This leading forum explores the state-of-the-art advances in rig technology and downhole operations and how to seamlessly integrate the two with minimal human intervention.
- 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.
- Oceanit has successfully set up a Joint Industry Partnership with two leading international oil companies, one national oil company, and one independent oil company for this work. The active involvement of the oil operators underscores the importance of this work to the industry.
Current Status (June 2015)
Oceanit has successfully demonstrated the response of Nanite to stress, temperature, fracture, and curing of the cement in laboratory settings and for only one mode of interrogation (electrical). Oceanit has developed the nanomaterial, cement compositions, electronic hardware, and software for this purpose and demonstrated the response of Nanite at lab scale. Researchers also developed novel electronics hardware and software to analyze the condition of Nanite for use in well cement monitoring. The dynamic electrical impedance spectra of Nanite have been used to detect cement curing, loading, and fracture. The electrical measurement form factor is being modified to accommodate concentric casings.
Oceanit has completed baseline monitoring and calibration of a cement curing process that demonstrates the response of a certain form factor (cube in this case) of the cement composition to perform the proof of concept (stress, temperature, fracture, and curing of the cement). Oceanit continues to work to further optimize these components based on the preliminary output from these tests.
Ongoing research effort focuses on comprehensive characterization of Nanite slurries using API recommended practices for cementing slurries and potentially detecting (i) top-of-cement and (ii) cement in an annular space between casing and formation using conventional and alternative non-traditional detection techniques. The goal is to complete material design and optimization, perform subscale proof testing and to identify currently utilized logging while drilling tools for early development and easy adoption of Nanite. The techniques of interest are the electrical resistivity characteristics and background acoustics already researched during the phase I effort and also the gamma ray emission/neutron detection researched during the phase II effort.
As part of project activities, Oceanit is also coordinating efforts with industry partners to identify potential test wells and specific wellbore integrity issues to be addressed if a Joint Industry Partnership member, or other industry partners, would decide to work with the recipient on a field study of the Nanite Cement after the project has been completed.
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)