Cementing with Tactical Blitz®:
CSI Technologies performed testing for a major DW operator to evaluate the following:
•Thickening Times and Compressive Strength
All test were performed in accordance with API RP 10B-2.
CSI Technologies’ Conclusions:
Can be mixed with cement up to 35 ppb, but with a practical limit of 20 ppb due to mixing issues at higher concentrations.
Has fines that increase slurry rheology.
Was able to plug a 1mm slot at 5 and 10 ppb*, but not a 3mm slot. 20 ppb was unable to plug a 3mm slot.
•The cement company’s LCM did not plug the 1mm nor the 3mm slot at the recommended concentration (2 ppb).
•A combination 2 ppb of cement company’s LCM and 20 ppb Tactical Blitz was unable to plug 3mm slot.
Had no appreciable impact on cement’s thickening time or compressive strength.
*10 ppb plug the 3mm slot to 400psi
Modeling and experience have shown that the required compressive strength is lower than typically seen in oil well cements.
Most cement sheaths fail in tension and not compression.
The increase in tensile strength provided by Tactical Blitz® will improve the cement sheath’s resistance to tensile failure.
The reduction in compressive strength does not adversely affect the cement sheath.
Both the Poisson’s Ratio and Young’s Modulus were reduced with Tactical Blitz®.
Though both are important in understanding the cyclically loading
withstood throughout the life of a cement sheath, there is no consensus
whether higher or lower values are “better”.
Additional Testing Initiated By TOP:
CSI Technologies recommended that TOP examine the following properties in addition to the test performed by the DW Operator:
•Compressive Strength (crush test)
•Splitting Tensile Strength
Permian Case Study #1
Loving County, TX – Brushy Canyon
The operator was running 7” or 7-5/8” casing in the second intermediate string typical to approximately 11,000’ to 12,000’.
A 5-1/2” Liner was placed at approximately 10,000’, but the 7” string was part of the frac string.
Several casing failures were previously experienced during frac operations due to poor cement jobs.
The operator requested that excess cement be pumped with losses expected.
The goal was to get cement to approximately 4,000’, up to the 9-5/8” shoe in a single stage job.
Cement density was 10.6 ppg.
•Six jobs have been pumped to-date in this area for this particular operator:
1. 10 bbls of cement was circulated to surface.
2. 56 bbls of cement was circulated to surface.
3. 1/2 of spacer makes it to surface.
4. 3/4 of spacer makes it to surface.
5. 74 bbls of cement was circulated to surface.
6. Trace of cement circulated to surface.
Permian Case Study #2
Lea County, NM – Capitan Reef
The operator was running 13-5/8” intermediate casing to 5,700’ through the Capitan reef (3,800’-5,600’).
Due to the challenges the reef presented, the operator planned to pump the first job through intermediate casing and cover as much of the reef as possible.
A second job would be pumped down the13-5/8” x 20” annulus to cover the remainder of the reef.
Permian Case Study #3
Reeves County, TX – Delaware, Basin
The operator was planning a two-stage cement job for their 9-5/8” intermediate casing set at 10,000’ (DV tool set at 5,200’).
Due to expected loss circulation in the Brushy Canyon Sand at 7,000’ - 7,500’, the operator planned to pump approximately 200 bbls of excess cement.
The goal was to get full cement returns to the DV tool in the first stage.
•The results for the first three cement jobs are as follows:
1. Circulated 198 bbls of cement off of the DV tool.
2. Circulated 200 bbls of cement off of the DV tool.
3. Circulated 200 bbls of cement off of the DV tool.
Note: The operator has since significantly reduced excess cement volume.
Permian Case Study #4
Reeves County, TX – Delaware, Basin (SWD Well)