Innovative Well Cementing Applications by Using Large Particle Sizes of Cement Additives

Abstract

Water-soluble cellulose based polymers such as hydroxyethyl cellulose (HEC), methylhydroxyethyl cellulose (MHEC), and carboxymethylhydroxyethyl cellulose (CMHEC) are commonly used additives to control important cement slurry properties like fluid loss, free fluid, and slurry stability. They typically hydrate quickly after contact with the mix water resulting in instant slurry viscosification and potential mixing difficulties especially at higher loadings. Adding cement dispersants to the cementing system design can facilitate slurry mixing but this does not always work out as expected. Sometimes incompatibilities between the dispersant and the other additives result in even more difficult slurry mixing. Furthermore the addition of dispersants to compensate mixing problems can enhance thermal thinning leading to severe settling issues once the slurry is exposed to the elevated downhole temperatures in the wellbore. To overcome these challenges, the use of large particle size cement additives to lower the surface mixing viscosity and the effect of important slurry properties were studied. The cement fluid loss, free fluid control, and slurry rheology performance of large particle size polymeric additives were evaluated in cement slurries. Different particle sizes for polymeric additive were tested in assorted cement densities and temperatures. Cement testing procedures, lab test results, and a case history is presented and discussed. The study demonstrates that the hydration of the cellulosic polymers is delayed as particle size of polymeric additives increases. It could be concluded that the use of larger size cellulosic polymers greatly facilitates slurry mixing, requires less mixing energy or reduces slurry mixing time, and results in a lower initial slurry rheology without negatively affecting other slurry properties (in some cases the fluid loss performance was even significantly improved).

Validation of a low field Rheo-NMR instrument and application to shear-induced migration of suspended non-colloidal particles in Couette flow

“…These normalized velocity profiles agree with the theoretical prediction of velocity from eq. (2) and demonstrate consistency between the low and high field instruments for a simple Newtonian liquid.…”

“…Transport of suspended non-colloidal solid particles is an important process in many industries, including oil and gas production [1] where the controlled placement of a cement slurry [2] and conveyance of solids by drilling fluids [3] are critical for safe and successful operations. Determining the hydrodynamic properties of non-colloidal large particle (diameter > 200 µm) suspensions is a challenge.…”

Comprehensive Review of Sealant Materials for Leakage Remediation Technology in Geological CO2 Capture and Storage Process

“…It showed that conventional Portland cement had a compressive strength decrease of 21.43%, while calcium-aluminate cement was only 5.16%. In addition, weight control agents, such as fly ash, , slag, , nanoparticles (e.g., microsilicon), ,− resins, , polymers, and many other swelling agents , can be added to adjust the CaO percentage, improve the cement density, and obtain better cement strength. In recent years, there have been many CO 2 -resistant additives developed to protect conventional Portland cement from acidic corrosion. − Vorderbuggen et al and Doan et al developed a cement additive (e.g., hydroxyethylcellulose, methyl hydroxyethylcellulose, and carboxymethyl hydroxyethyl cellulose) that can create an insoluble barrier when it encounters an acid attack. Laboratory tests showed that this additive performed well under specific pressure and temperature in brines saturated with CO 2 for weeks.…”

“…In recent years, there have been many CO 2 -resistant additives developed to protect conventional Portland cement from acidic corrosion. − Vorderbuggen et al and Doan et al developed a cement additive (e.g., hydroxyethylcellulose, methyl hydroxyethylcellulose, and carboxymethyl hydroxyethyl cellulose) that can create an insoluble barrier when it encounters an acid attack. Laboratory tests showed that this additive performed well under specific pressure and temperature in brines saturated with CO 2 for weeks.…”

Shale Cuttings Addition to Wellbore Cement and Their Effect on Unconfined Compressive Strength

“…Cellulose materials are often used in cement slurries to prevent fluid loss but have proved to be unreliable in both high-and low-temperatures as well as in areas with a high salt concentration [8]. Examples of cellulose materials commonly used in wellbore cement include hydroxyethyl cellulose (HEC), methyl hydroxyethyl cellulose (MHEC), and carboxymethyl hydroxyethyl cellulose (CMHEC), which when hydrated, immediately increase the slurry viscosity [9]. Cellulose materials can prove problematic in that this increased viscosity can lead to issues with pumping the slurry.…”