Evaluation of Specialized Cement System for Long-Term Steam Injection Well Integrity

Abstract Assurance of well integrity is critical and important throughout the entire well's life cycle. Pressure build-up between cemented casings annuli has been a major challenge all around the world. Cement is the main element that provides isolation and protection for the well. The cause for pressure build-up in most cases is a compromise of cement sheath integrity that allows fluids to migrate through micro-channels from the formation all the way to the surface. These problems prompt cementing technologists to explore new cementing solutions, to achieve reliable long-term zonal isolation in these extreme conditions by elevating shear bond strength along-with minimal shrinkage. The resin-cement system can be regarded as a novel technology to assure long term zonal isolation. This paper presents case histories to support the efficiency and reliability of the resin-cement system to avoid casing to casing annulus (CCA) pressure build-up. This paper presents lab testing and application of the resin-cement system, where potential high-pressure influx was expected across a water-bearing formation. The resin-cement system was designed to be placed as a tail slurry to provide a better set of mechanical properties in comparison to a conventional slurry. The combined mixture of resin and cement slurry provided all the necessary properties of the desired product. The slurry was batch-mixed to ensure the homogeneity of resin-cement slurry mixture. The cement treatment was performed as designed and met all zonal isolation objectives. Resin-cement’s increased compressive strength, ductility, and enhanced shear bond strength helped to provide a dependable barrier that would help prevent future sustained casing pressure (SCP). The producing performance of a well depends in great part on a good primary cementing job. The success of achieving zonal isolation, which is the main objective of cementing, is mainly attributed to the cement design. The resin-cement system is evolving as a new solution within the industry, replacing conventional cement in many crucial primary cementing applications. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technology can be a key resource for such operations in the future. The paper describes the process used to design the resin-cement system and how its application was significant to the success of the jobs. By keeping adequate strength and flexibility, this new cement system mitigates the risk of cement sheath failure throughout the life of well. It provides a long-term well integrity solution for any well exposed to a high-pressure environment.

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Customized Insulating Packer Fluid Improves Steam-Injection-Well Integrity

10.2118/133679-ms ◽

2010 ◽

Author(s):

Jay K. Turner ◽

Ryan Ezell ◽

Brian Hugh Macmillan ◽

Dodie Ezzat

Keyword(s):

Steam Injection ◽

Injection Well ◽

Well Integrity

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Near-surface tilt response to steam injection into a tar sands formation

Canadian Journal of Earth Sciences ◽

10.1139/e90-141 ◽

1990 ◽

Vol 27 (10) ◽

pp. 1312-1315 ◽

Cited By ~ 1

Author(s):

J. S. Rogers ◽

F. W. Jones ◽

M. E. Ertman ◽

J. Thibault

Keyword(s):

Hydraulic Fracture ◽

Mercury Level ◽

Steam Injection ◽

Injection Well ◽

Near Surface ◽

Tar Sands ◽

Injection Process ◽

Tilt Response ◽

Fast Fracture

Two biaxial mercury-level borehole tiltmeters located at moderate depth (20 m) and 91 m horizontally distant from the injection well have been used to monitor the effects of a fast hydraulic fracture and subsequent steam injection in a tar sands formation at a depth of 230 m. Tilt vectors are determined for the maximum tilts during the fracture, and the long-term tilt migration associated with the steam-injection process is monitored. The tilt associated with the fast fracture is of the order of 1–2 μrad, and the long-term tilt increased as much as 240 μrad over the 500 day monitoring period, and appeared to approach a limit. The long-term tilt migration generally follows the same orientation as the initial tilt due to the fast fracture.

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Assurance of Long-Term Well Integrity in Highly Corrosive Downhole Environment

10.2118/207015-ms ◽

2021 ◽

Author(s):

Mohammad Arif Khattak ◽

Agung Arya Afrianto ◽

Bipin Jain ◽

Sami Rashdi ◽

Wahshi Khalifa ◽

...

Keyword(s):

Gas Production ◽

Simulation Software ◽

Successful Implementation ◽

Horizontal Section ◽

Well Integrity ◽

Well Design ◽

Cement System ◽

Zonal Isolation ◽

Fit For Purpose

Abstract Portland cement is the most common cement used in oil and gas wells. However, when exposed to acid gases such as carbon dioxide (CO2) and hydrogen sulfide (H2S) under downhole wet conditions, it tends to degrade over a period of time. This paper describes the use of a proprietary novel CO2 and H2S resistant cement system to prevent degradation and provide assurance of long-term wellbore integrity. The CO2-resistant cement was selected for use in one of the fields in Sultanate of Oman after a well reported over 7% CO2 gas production resulting in well integrity failure using conventional cements. The challenge intensified when the well design was modified by combining last two sections into one long horizontal section extending up to 1,600 m. The new proposed cement system was successfully laboratory- tested in a vigorous CO2 environment for an extended period under bottomhole conditions. Besides selecting the appropriate chemistry, proper placement supported by advanced cement job simulation software is critical for achieving long-term zonal isolation. The well design called for a slim hole with 1,600 m of 4 ½-in liner in a 6-in horizontal section where equivalent circulating density (ECD) management was a major challenge. An advanced simulation software was used to optimize volumes, rheologies, pumping rates, and ECDs to achieve the desired top of cement. The study also considered a detailed torque and drag analysis in the horizontal section, and fit- for-purpose rotating-type centralizers were used to help achieve proper cement coverage. To date, this cement system has been pumped in 32 wells, including 24 with 6-in slimhole horizontal sections with no reported failures. The paper emphasizes the qualification and successful implementation of fit-for-purpose design of CO2- and H2S-resistant cement as well as optimized execution and placement procedures to achieve long-term zonal isolation and well integrity in a complex slimhole horizontal well design.

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