Self Sealing Cement System Enables Prevention of Water Intrusion and Long Term Zonal Isolation in Um Gudair Field: A Case Study in West Kuwait

Summary The bulk shrinkage of cement sheaths in oil wells can result in loss of long-term zonal isolation. Expansive additives are used to mitigate bulk shrinkage. To compensate effectively for bulk shrinkage during the late plastic phase and the hardening phase of the cement system, the performance of the expansive additive needs to be regulated considering the actual cement system and placement conditions. This paper presents an introductory investigation on the potential engineering of nanosized magnesium oxide (MgO) (NM) through heat treatment for use as an expansive agent in oilwell-cement systems. In this study, the bulk shrinkage of a cement system was mitigated by introducing NM with designed reactivity to the fresh cement slurry. The reactivity of NM was controlled by heat treatment. A dilatometer with corrugated molds was used to measure the linear strain of samples cured at 40°C and atmospheric pressure. The effect of NMs differing in reactivity on tensile properties of cement systems cured for 3 days at 40°C was examined by use of the flattened Brazilian test. The reactivity of the NM played a key role in controlling the bulk shrinkage of the cement system. Addition of only 2% NM by weight of cement (BWOC) with appropriate reactivity was sufficient to maintain expansion of the cement system. Adding NM to the cement system also resulted in improved mechanical flexibility. The NM with highest reactivity caused the largest reduction in Young's modulus at 3 days and, in general, the ratio of tensile strength to Young's modulus improved through the addition of NM to the cement system. Our work demonstrates that controlling the reactivity of the additive is a promising method to mitigate bulk shrinkage of cement systems and thereby to sustain the mechanical properties of the cement sheath in the oil well at an acceptable level.

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Application of Resin-Cement Blend to Prevent Pressure Build-Up in Casing to Casing Annulus CCA: A Novel Approach to Improve Well Integrity

10.2118/202103-ms ◽

2021 ◽

Author(s):

Wajid Ali ◽

Freddy Jose Mata ◽

Ahmed Atef Hashmi ◽

Abdullah Saleh Al-Yami

Keyword(s):

High Pressure ◽

Shear Bond Strength ◽

Resin Cement ◽

Cement Slurry ◽

Well Integrity ◽

Cement System ◽

Zonal Isolation ◽

Primary Cementing ◽

Cement Sheath

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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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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Novel Steam-Resilient Cement System for Long-Term Steam Injection Well Integrity: Case Study of a Steamflooded Field in Indonesia

10.2118/170048-ms ◽

2014 ◽

Cited By ~ 2

Author(s):

Amir Gheisar Salehpour ◽

Elena Pershikova ◽

Alice Chougnet-Sirapian ◽

Salim Taoutaou ◽

Diyah Ayu Adiningtyas

Keyword(s):

Steam Injection ◽

Injection Well ◽

Well Integrity ◽

Cement System

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Novel Steam-Resilient Cement System for Long-Term Steam Injection Well Integrity: Case Study of a Steamflooded Field in Indonesia

10.2118/166994-ms ◽

2013 ◽

Author(s):

Amir Gheisar Salehpour ◽

Diyah Ayu Adiningtyas ◽

Alice Chougnet-Sirapian ◽

Elena Pershikova ◽

Salim Taoutaou

Keyword(s):

Steam Injection ◽

Injection Well ◽

Well Integrity ◽

Cement System

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Caregivers' Perceptions of Speech-Language Pathologist Talk About Child Language and Literacy Disorders

American Journal of Speech-Language Pathology ◽

10.1044/2020_ajslp-20-00049 ◽

2020 ◽

Vol 29 (4) ◽

pp. 2049-2067

Author(s):

Karmen L. Porter ◽

Janna B. Oetting ◽

Loretta Pecchioni

Keyword(s):

Language And Literacy ◽

Collective Case Study ◽

Study Approach ◽

School Aged Children ◽

Speech Language Pathologist ◽

Therapy Goals ◽

Semistructured Interviews ◽

Types Of Information

Purpose This study examined caregiver perceptions of their child's language and literacy disorder as influenced by communications with their speech-language pathologist. Method The participants were 12 caregivers of 10 school-aged children with language and literacy disorders. Employing qualitative methods, a collective case study approach was utilized in which the caregiver(s) of each child represented one case. The data came from semistructured interviews, codes emerged directly from the caregivers' responses during the interviews, and multiple coding passes using ATLAS.ti software were made until themes were evident. These themes were then further validated by conducting clinical file reviews and follow-up interviews with the caregivers. Results Caregivers' comments focused on the types of information received or not received, as well as the clarity of the information. This included information regarding their child's diagnosis, the long-term consequences of their child's disorder, and the connection between language and reading. Although caregivers were adept at describing their child's difficulties and therapy goals/objectives, their comments indicated that they struggled to understand their child's disorder in a way that was meaningful to them and their child. Conclusions The findings showed the value caregivers place on receiving clear and timely diagnostic information, as well as the complexity associated with caregivers' understanding of language and literacy disorders. The findings are discussed in terms of changes that could be made in clinical practice to better support children with language and literacy disorders and their families.

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