SAFE-CARB

Ground marble bridging agent

Schlumberger Oilfield Services

SAFE-CARB ground marble bridging agent is a high-purity, acid-soluble calcium carbonate used as a bridging and weighting agent in drilling, drill-in, workover, and completion fluids. Compared with limestone, the agent features higher hardness and purity, providing better acid solubility.

This calcium carbonate bridging and weighting agent can be used in fluids ranging from conventional drilling fluids to advanced drill-in fluid systems, including

It can also be used with SEAL-N-PEEL fluid loss control pill to seal the inside of sand-control completion assemblies as a bridging agent and fluid-loss additive. Use OPTIBRIDGE software to select the optimal blend of SAFE-CARB agent to reduce fluid loss and minimize fluid and solids invasion.

The agent can also be added on a periodic basis for seepage control to limit losses to lost circulation and leak-off to high-permeability formations. It is particularly effective when drilling with high differential pressures caused by an overbalanced condition or when drilling depleted zones. Treatments range from 2 to 10 sacks per hour when used as a preventative measure. For depleted-zone drilling or induced-fracture applications, SAFE-CARB agent is most effective when used with

 
Product Name Median Particle Size (d50), um  Recommended Test Procedure
Product Name SAFE-CARB 2
Median Particle Size (d50), um  1–4  Recommended Test Procedure Laser light scattering
Product Name SAFE-CARB 10
Median Particle Size (d50), um  6–15
Recommended Test Procedure Laser light scattering
Product Name SAFE-CARB 20  Median Particle Size (d50), um  16–29
Recommended Test Procedure Laser light scattering
Product Name SAFE-CARB 40
Median Particle Size (d50), um  31–48
Recommended Test Procedure Laser light scattering
Product Name SAFE-CARB 140
Median Particle Size (d50), um  120–180
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 250 Median Particle Size (d50), um  225–300
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 500
Median Particle Size (d50), um  430–520
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 600
Median Particle Size (d50), um  550–650
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 750
Median Particle Size (d50), um  655–800
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 1400
Median Particle Size (d50), um  1,200–1,550
Recommended Test Procedure Dry-sieve analysis
Product Name SAFE-CARB 2500
Median Particle Size (d50), um  2,100–2,700
Recommended Test Procedure Dry-sieve analysis

Median particle size (d50) is reported as a size range due to variations in the manufacturing and grinding process. If a precise size distribution of a product is critical to a drilling operation, it should be measured with the appropriate recommended test procedure using samples that are representative of those expected to be used in that operation. Nominal d10 and d90 values are available upon request.

Imperial measurements

Volume of SAFE-CARB agent in lbm/bbl = (980 [w2w1])/(23.3–w2)

where
w1 = initial mud weight in lbm/galUS
w2 = desired mud weight in lbm/galUS.

Metric measurements

Volume of SAFE-CARB agent in kg/m3 = (2,800 [w2w1])/(2.8–w2)

where
w1 = initial mud weight in relative density
w2 = desired mud weight in relative density.

 
Typical Physical Properties
Typical Physical Properties Physical appearance Typical Physical Properties White powder
Typical Physical Properties Relative density Typical Physical Properties 2.7–2.8
Typical Physical Properties Solubility in water at 212 degF [100 degC] Typical Physical Properties 0.0035 g/100 mL
Typical Physical Properties Solubility in 15% HCl at 76 degF [24.4 degC] Typical Physical Properties ≥97%

Applications

  • Controlling fluid loss, density, and bridging in a range of fluids
  • Sealing of sand-control completion assemblies

Advantages

  • Minimized formation damage through high-quality, acid-soluble material design
  • Effective bridging, especially when using OPTIBRIDGE bridging agent selection software to design an optimized, application-specific blend
  • Simplified method of identifying the approximate d50 of agent
  • High-hardness ground marble makeup that resists particle-size degradation
  • Essentially inert for minimized effect on fluid properties 

Toxicity and handling

Bioassay information is available upon request. No claim of personal safety is intended nor implied by the use of the name “SAFE” in this product. Handle as an industrial chemical, wear protective equipment, and observe the precautions as described in the material safety datasheet (MSDS).

Packaging and storage

SAFE-CARB agent is packaged in 50-lbm [22.7-kg], 55-lbm [25-kg], and 110-lbm [50-kg] multiwall paper sacks. Store in a dry, well-ventilated area. Keep container closed when not in use. Store away from incompatibles. Follow safe warehousing practices regarding palletizing, banding, shrink-wrapping, and stacking.