CG910S–Advanced Low-Temperature Accelerating Fluid Loss Additive for Cementing Operations

Oil well cementing plays a vital role in ensuring well integrity, zonal isolation, and long-term performance of oil and gas wells. Cement slurries must be designed to meet various operational and geological conditions, especially in complex and extreme environments. Among the numerous challenges faced in cementing operations, low-temperature conditions pose significant issues—particularly with regard to slow setting times and uncontrollable fluid loss. The performance of cement slurries is considerably influenced by ambient temperature, which affects hydration kinetics, thickening behavior, and filtration control.

CG910S, a specialty additive developed by Kelioil, is a high-performance low-temperature accelerating fluid loss additive engineered specifically for cementing jobs conducted at temperatures below 60°C. It not only addresses the common challenges associated with low-temperature cementing but also contributes to improved operational efficiency, enhanced early strength, and reduced downhole risks.

Cementing operations conducted during harsh winters.

Under such conditions, cement hydration is significantly slowed, resulting in long setting times and delayed strength development. A major consequence is the extended waiting-on-cement time, which increases rig time and overall operational costs. Moreover, inadequate filtration control can lead to loss of cement slurry into the formation, causing poor zonal isolation, well control issues, and even early cement job failure.

In response to these challenges, operators seek cement additives that can accelerate hydration while maintaining excellent fluid-loss control. CG910S has been meticulously developed to meet these demanding requirements.

CG910S is a specialized, multifunctional additive formulated using a blend of proprietary polymers and accelerators. The additive is optimized to:

Accelerate thickening time to shorten the pumpability window and ensure faster setting of the slurry.

Enhance early compressive strength, enabling quicker transition to subsequent operations.

Control fluid loss to industry-accepted standards even under low-temperature and low-pressure conditions.

CG910S is especially effective when used in combination with dispersants, retarders, and other cementing additives tailored for low-temperature environments.

Key Benefits of CG910S

1. Accelerated Setting Time

CG910S significantly reduces both the initial and final setting times of cement slurries in low-temperature conditions. This rapid setting capability allows operators to resume drilling or completion activities in a shorter timeframe, thus reducing non-productive time.

2. Enhanced Early Strength Development

By accelerating the hydration reaction, CG910S promotes early strength development. This is critical for maintaining structural integrity in surface casings and shallow intervals, where fast pressure-bearing capacity is needed. Compressive strength measurements taken at 8 hours post-placement have shown strength gains of 50% to 80% higher than control samples.

3. Superior Fluid Loss Control

CG910S also functions as an effective fluid-loss additive, helping maintain slurry consistency and preventing excessive fluid migration into the formation. This improves bonding quality and minimizes the risk of channeling, gas migration, or micro-annuli formation.

4. Excellent Compatibility and Stability

The product demonstrates excellent compatibility with other common cementing additives, including retarders, dispersants, anti-gas migration agents, and defoamers. It can be blended into various cement slurry designs without compromising rheological stability or pumpability.

The versatility of CG910S allows it to be deployed in a broad range of low-temperature cementing operations. Below are some typical scenarios where CG910S delivers significant operational benefits.

1. Shallow Well Cementing

In shallow wells, formation temperatures are often well below 60°C. Cement slurries in such environments tend to exhibit prolonged setting times, leading to inefficient operations and increased risks of gas migration. CG910S enables faster setting even in these low-temperature zones, allowing for effective zonal isolation and reduced waiting time before resuming operations. 

2. Surface Casing in Deep and Ultra-Deep Wells

In deep and ultra-deep well construction, the surface casing is typically cemented at shallow depths where the temperature remains low, regardless of the high bottomhole temperatures expected later. CG910S is especially effective in these early-stage cementing jobs, where establishing a competent seal is critical for the integrity of subsequent drilling stages. Its rapid strength development ensures the casing is secure before applying additional load from deeper drilling.

3. Cementing in Permafrost or Arctic Environments

Permafrost zones, commonly found in northern oilfields (e.g., Alaska, Siberia, Canada), present extreme challenges. Slurry freezing, delayed setting, and poor bonding are frequent problems. CG910S, due to its accelerated hydration and stable fluid loss properties, helps prevent slurry freezing and ensures strong bonding to the wellbore wall. This contributes to long-term wellbore integrity, even in sub-zero surface conditions.

4. Cementing During Cold Weather

Even outside of arctic regions, cementing operations conducted in winter months often face temperature-related delays and risks. CG910S is formulated to remain active and effective in these lower temperature ranges, maintaining performance consistency without requiring complex heating equipment or additional additives.

Recommendations for Use

To fully leverage the benefits of CG910S, certain best practices should be followed in slurry design and field implementation:

Recommended Dosage

The typical recommended dosage of CG910S is 1.2-2.5% by weight of cement (BWOC), depending on:

Slurry density and composition

Desired setting time reduction

Target fluid-loss control level

Specific downhole temperature and pressure