CG613: Reduces fluid loss and prevents reversal in one step

In oil and gas exploration, effective cementing is the cornerstone of safe and productive well operations. As the industry advances into deeper, more complex, and geologically diverse formations, the challenges related to cementing have intensified. Among these, two of the most critical challenges are fluid loss and the reversal of cement strength under temperature fluctuations, especially at medium and low temperatures. Kelioil’s CG613 anti-reversal fluid loss additive was designed specifically to address these challenges in a single, innovative solution.

CG613 is a polymer-based fluid loss additive that provides excellent control of filtrate loss while uniquely preventing the reversal of thickening time and compressive strength development—a phenomenon that plagues many conventional cement systems operating at 158°F (70°C) and 194°F (90°C). This dual-functionality positions CG613 as a next-generation additive that not only safeguards zonal isolation but also enhances overall well integrity.

Understanding Cementing Challenges

Cementing serves multiple critical functions: it secures the casing in place, prevents fluid migration between formation zones, and protects the wellbore from corrosive formation fluids. For cement to perform effectively, it must exhibit predictable thickening time, controlled fluid loss, and consistent strength development.

Fluid Loss: When drilling mud is displaced by cement slurry, part of the liquid phase in the cement can leak into the formation. Excessive fluid loss can cause premature setting of the cement, increased viscosity, poor bonding, and even loss of circulation. Moreover, filtrate invasion into productive formations may result in formation damage.

Strength Reversal: This issue refers to the loss of compressive strength after initial gain, often due to temperature instability or improper hydration. It is a significant concern in cementing jobs conducted at medium and low temperatures where hydration reactions are inherently slower. If left unaddressed, strength reversal can compromise the long-term sealing capability of the cement sheath.

Shortcomings of Traditional Additives

Conventional fluid loss additives typically provide acceptable performance at high temperatures but struggle at lower thermal ranges. Many of these additives cannot ensure a consistent hydration profile, and under certain conditions, they may even accelerate free water separation or alter the slurry’s rheology, leading to unpredictable setting behavior and strength development.

Traditional cement systems often require multiple additives. However, multi-component systems increase logistical complexity, raise compatibility risks, and inflate operational costs.

CG613: An Integrated Solution

Recognizing the need for an advanced, multifunctional additive, Kelioil developed CG613 using a specially engineered polymer matrix. This additive was tailored to provide superior fluid loss control while stabilizing the hydration reaction of cement under temperature-sensitive conditions. Here’s how CG613 redefines cementing performance:

1. Advanced Polymer Structure

CG613’s polymer matrix forms a dense, uniform filter cake on the borehole wall, effectively sealing pores and fractures. This minimizes filtrate invasion, thereby maintaining slurry stability and rheology.

2. Anti-Reversal Technology

Unlike typical additives, CG613 actively stabilizes the thickening curve of cement slurry. This property is crucial for medium to low-temperature applications where reversals are common.

3. Simplified Cement Formulation

Because CG613 addresses two major cementing challenges simultaneously, it reduces the need for additional additives. This simplification enhances mixing efficiency, minimizes on-site errors, and promotes better quality control. Fewer additives also translate into lower operational costs and reduced risk of chemical incompatibility.

Performance Testing and Laboratory Evaluation

CG613 has been subjected to a comprehensive suite of laboratory tests to verify its performance under field-representative conditions. The results highlight its effectiveness across multiple critical parameters:

Thickening Time Stability: Slurry systems containing CG613 show no inversion in thickening profile over time.

Compressive Strength Development: Cement samples maintain a linear increase in compressive strength without degradation, even after 72 hours of curing.

Environmental and Economic Considerations

CG613 not only improves technical performance but also offers environmental and economic advantages. Its efficient formulation reduces the need for excessive chemical additions, thereby lowering the environmental impact. The reduced volume of required materials also means fewer transportation requirements and lower carbon footprint.

From an economic standpoint, fewer additives mean lower procurement and storage costs. Additionally, faster strength development enables earlier rig release, contributing to significant time and cost savings.

Operational Guidelines

For optimal performance, the recommended dosage of CG613 ranges from 0.6-2.5% by weight of cement (BWOC), depending on well conditions and cement system composition. It is compatible with both freshwater and saltwater slurries. Standard mixing procedures can be used, and no special equipment is required for blending or pumping.

Recommended Practices:

Pre-job slurry testing is advised to determine the precise dosage.

Ensure homogeneous mixing for consistent dispersion.

Store in a dry, cool place to maintain product integrity.

Kelioil’s CG613 anti-reversal fluid loss additive represents a significant advancement in cementing technology. By addressing two of the most persistent challenges—fluid loss and strength reversal—in a single product, CG613 offers a robust, reliable, and cost-effective solution for medium and low-temperature cementing operations. Its performance has been validated both in the lab and in the field, and its environmental and operational advantages make it a preferred choice for cementing engineers worldwide.

In a sector where well integrity and operational efficiency are paramount, CG613 provides the assurance of stability, safety, and success. With this innovative additive, operators can confidently tackle challenging formations, reduce non-productive time, and achieve superior zonal isolation—cementing their way to long-term well performance.