A Technically Advanced LCM with Dramatic Performance
Better than Fiber and Graphite with No Sheen No Mess and No Change in Fluid Viscosity
XP-911 is a unique seepage loss control agent with a particle size distribution of fewer than 50 microns to greater than 200 microns. Each particle is shaped like a bead with different diameters following a specific design and intent for ideal particle size distribution.
Each particle bead is composed of inert and crush resistant modified carbon that will not react and corrode metal surfaces and is not abrasive. The basic chemistry is in the same class as all carbon that includes graphite and coke but modified for improved sealing properties.
The particle size distribution provides fine, medium and coarse beads in one bag. The smallest particle is more massive than five microns, which is the average pore size for production reservoirs and therefore will not clog the pore spaces. Appropriate tests conducted with five-micron disks at the 500-psi bottom and three psi top show zero reservoir impairment.
Essentially XP-911 is a faux “Synthetic Graphite” that incorporates all the attributes and excludes the disadvantages. The product has been tested for use in downhole motors and found to be compatible with no abrasion.
XP-911 retains its shape and size for improved particle size distribution that remains throughout the cycle from the hopper to thief zone.
The unique bead shape and the distribution pattern provides phenomenal sealing by a “Sea Wall” effect with no change in fluid viscosity regardless of the mud weight and with as much as 50 pounds per barrel added.
The bead shape provides a ball bearing effect for improved lubricity, but it’s the sealing effect that dramatically reduces torque and drag because whole mud loss reduction is directly proportional with the decrease in torque and drag.
The superior sealing ability allows low usage requirement. Best cost/performance is achieved by adding the material in sweeps at 15 pounds per barrel. The sweep will go directly to the thief zone.
Stop adding material when it is observed coming over the shaker screen. It is not recommended to keep any LCM circulating in the system because all LCM of any type and design will be screened out and wasted.
XP-911 Versus Cellulose Fiber
A generic #7 mud was prepared using 22 pounds per barrel (PPB) bentonite, 4 ppb CLS, one PPB Caustic Soda, 7 PPB Sea Salt, One PPB PAC L/V, 0.25 PPB xanthan Gum to ensure no settling and 100 PPB barite.
Two samples were prepared with 6 PPB LCM added to each. Sample one had 6 PPB commercial grade Cellulose Fiber Sample two had 6 PPB XP-911.
All samples were hot rolled @ 150º F for 16 hours. Each sample was tested in a permeability plugging test apparatus with a 90-micron disk at 2000 PSI.
|Sample One||Fine Cellulose Fiber||Sample Two XP-911|
|30 Minute||4.6 x 2||1.6 x 2|
XP-911 Versus Coarse Cellulose Fiber
Test was conducted with a coarse cellulose fiber in a 190-micron disk.
Sample one had 15 PPB Coarse Fiber
Sample two had 15 PPB XP-911
Coarse Fiber XP-911
32 cc 3.2 cc
Note: The viscosity of the mud may have been a factor for the high PPT for the coarse fiber. You need 15 PPB to obtain sealing, but the viscosity of the slurry was almost three times higher with the fiber. Similar tests with this particular fiber show total PPT values from 15 to 30, while XP-911 remains relatively constant and very little change in viscosity even with 50 PPB of material included.
XP-911 Vs. Old School LCM Cure All
A base mud was prepared with 25 pounds per barrel (PPB) Natural Gel, 20 PPB Rev Dust, 6 PPB Lignosulfonate, 2 PPB lime, 1 ppb caustic soda, 2 PPB 1-100 cornstarch and 200 PPB barite.
Sample One Added
- 15 PPB of the following mixture:
- 12.5 % Nut Plug Medium
- 12.5% Nut Plug Fine
- 25% Calcium carbonate
- 25% Mica Coarse
- 25% Commercial Available Fiber
Sample Two Added
15 PPB XP-911
Both samples were hot rolled at 175º F for 12 hours. The rheology was taken after stirring 5 minutes in a Hamilton Beech mixer and heated to 110º F. The PPT was obtained at 110º F, since temperature stability was not a factor, 2000 PSI with a 190-micron disk.
|Sample One||Sample Two|
|G/S 10 Sec||4||0|
|G/S 10 Min||80||4|
|30 Min Loss||6||5.6|
XP-911 does not plug pore spaces. It seals using a sea wall effect and collects at the thief zone forming a tight seal. In a production zone, where the pressure is higher than the hydrostatic head pressure, the LCM would unseal, and there would be zero reservoir impairment.
The real test is how the product performs under pressure in the Permeability Plugging Tester in an adequately prepared drilling mud. The results below were conducted by an independent laboratory and indicate XP-911 has better sealing than does synthetic graphite.
XP-911 competes favorably with all graphite materials and in all particle size disks. The secret is the particle size distribution that remains constant throughout the drilling process. XP-911 does not infringe on any known patent.
XP-911 is inert and will not dissolve in any known solvent. It is completely environmentally safe except for dust.