Smart Expandable Cement Additive to Achieve Better Wellbore Integrity

Abstract

One of the serious challenges encountered in cementing oil and gas wells is the failure of the cement sheaths and its debonding from casing or formation rock. Shrinkage of the cement during setting is identified as one of the driving factors behind these issues. Some expansive cement systems have been developed in the oil and gas industry to compensate for the shrinkage effect. All the expansive additives which have been developed so far have chemical reactions with the cement itself that would significantly impact the mechanical strength of the cement. In this paper, we present a new class of polymer-based expandable cement additive particles which are made of shape memory polymers (SMP). This class of polymers is designed to expand to the required extent when exposed to temperatures above 50–100 °C (122–212 °F) which is below the temperature of the cementing zone. It is notable that expansion occurs after placement of the cement but before its setting. The API RP 10 B-2 and 5 have been followed as standard test methods to evaluate expansion and strength of the cement slurry after utilizing the new additive. The proposed additive does not react with the water or cement content of the slurry. Mechanical evaluation tests confirm the potential benefit of this additive without any deteriorative effect on mechanical properties or setting time of the cement paste and significant impact on its mechanical properties. Hence, this additive would provide a reliable way to prevent cement channeling, debonding, and fluid migration to upper formations.

Hydrogen Impact on Cement Integrity during Underground Hydrogen Storage: A Minireview and Future Outlook

“…A shape memory polymer (SMP) is a new type of expandable cement additive particle that can expand when exposed to temperatures above 50−100 °C while increasing the density and compressive strength of the cement seal. 89 This new type of cement additive may provide a solution to concerns regarding the wellbore integrity during gas storage. The degree of linear expansion is directly proportional to the amount of SMP added, making it easy to achieve the desired level of expansion by adjusting the percentage of SMP added to the weight of cement.…”

A Hybrid Syntactic Foam-Based Open-Cell Foam with Reversible Actuation

“…They can also be used for floatable structures like bridges. − SMP foams are also considerably more compressible, which is advantageous for their handling and storage. A compressible SMP can be beneficial for applications that require expanding an orifice like a well − or dilating a blood vessel . Open-cell SMP foams can also be used as tissue scaffolds for biomedical applications, , including embolic vascular devices, scaffolds for filling bone defects, hemostatic sponges, soft tissue scaffolds, drug delivery platforms, and treatment of intracranial aneurysms .…”

Application of a Synthetic Polymer Nanocomposite Latex in a Wellbore Cement Slurry for Gas Blockage Functions

“… 27 Polymer latexes have also recently been evaluated as candidates for controlling gas migration by optimizing gelatinous properties and increasing the surface tension of molecular liquids in the cement slurry phase. 28 …”

“…Applications of polymeric materials as additives to improve the mechanical properties of wellbore cement have been the subject of many research projects . Polymer latexes have also recently been evaluated as candidates for controlling gas migration by optimizing gelatinous properties and increasing the surface tension of molecular liquids in the cement slurry phase …”