|“Nanite” for Better Well-Bore Integrity and Zonal Isolation
||Last Reviewed 6/14/2016
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, HI 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)
- Developed and tested an updated high-speed electrical resistivity tool for Nanite with faster sample rates, greater flexibility in the selection of calibration modes, and direct connection to a single board computer.
- Investigated different modified nanomaterial additives and processing methods for further improving admixture performance for Nanite load sensitivity.
- Successfully tested the load response of Nanite in alternative form factors concluding that Nanite is scalable to various form factors.
- Deployed an in-ground Nanite-based weigh-in-motion sensor system with multiple distributed Nanite sensors at a State of Hawaii Weigh Station for continuous monitoring of vehicle loads, thus gaining valuable field deployment experience with remote detection operations.
- Designed electrical and electromagnetic measurement systems for sub-scale testing of Nanite interrogation techniques.
- Developed a reliable and repeatable electrical measurement technique to assess well cement stress and condition.
- Selected a single optimized Nanite admixture formulation for deployment studies.
- Optimized specimen preparation procedures resulting in substantially improved uniformity and yield.
- Performed numerical modelling on the mechanical stress distribution in Nanite specimens under compressive loading.
- Developed improved data analysis protocols enabling tracking of specimen performance over time and the use of data mining techniques to aid in development of electrical behavior models.
- Continued development of a high-speed electrical resistivity tool with enhanced sensitivity.
- The work conducted under this award has allowed Oceanit to engage a major international operating company to use a Nanite derivative for deepwater well cement monitoring.
- Oceanit has consulted a drilling and production technical advisor with a major international operating company regarding deployment opportunities for Nanite who confirmed that Nanite is appropriate for determining well cement integrity using a continuous monitoring system or downhole tool.
- Received Budget Period II continuation authorization.
- Hosted DOE program manager site visit in May 2015.
- Demonstrated a 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 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:
- On November 23, 2015 Oceanit hosted its 30th anniversary celebration providing technology demonstrations to hundreds of visitors from the business community and government.
- On November 16, 2015 Oceanit briefed a deepwater technology advisor from a major international operating company (a joint industry partner) who recommended Nanite technology for a broad range of well cement monitoring applications.
- Dr. Vinod Veedu visited the offices of a major national operating company (a joint industry partner) from November 6 - 9, 2015, to provide an in person briefing on the project status.
- Oceanit hosted a senior executive from a major international operating company (a joint industry partner) in Honolulu, HI on October 20, 2015 for a briefing on nanite and Oceanit’s capabilities.
- 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 2016)
Oceanit is continuing to develop a comprehensive model of Nanite electrical resistivity accounting for temperature, pressure, curing state, and cement condition. Investigations are also underway to study the effects of using modified nanomaterial additives of various densities in the Nanite formulation to further optimize load sensitivity. Oceanit is continuing to test Nanite in different form factors to address scaling the material for downhole applications and conformance to varying geometries. Initial results show scalability is achievable with an impedance tool that covers the relevant impedance range, but further investigation is required to test with the various form factors and optimized impedance tools. To validate compatibility with downhole conditions and common wellbore fluids, Oceanit has prepared Nanite admixtures for testing at an industry certified cement analysis laboratory in June 2016.
The adoption of advanced data processing and analysis techniques are extending the opportunities for data mining the large quantities of experimental data generated in the course of the project. The ongoing research effort focuses on the development of deployment methods and integrated systems for monitoring well cement integrity in preparation for field trials. This work includes design and implementation of tools for continuous or intermittent evaluation. Oceanit is focusing on such measurements to detect (i) top-of-cement, (ii) cement condition in an annular space between casing and formation, and (iii) plug integrity in abandoned wells. In addition to electrical resistivity techniques, Oceanit is also investigating electromagnetic techniques to interrogate Nanite deployed in downhole well-bore casings.
As part of project activities, Oceanit continues to coordinate 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 (email@example.com or 304-285-4268)
Oceanit – Vinod Veedu (vveedu@OCEANIT.COM or (713) 357-9622)