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ULIA is a field proven additive that allows building a low invasion drilling fluid which improves wellbore circumferential stress, prevents hole collapse and effectively controls mud losses. ULIA significantly reduces fluid invasion into matrix permeability and micro-fractures by forming a very low permeability, yet acid soluble, barrier across the exposed formation. This barrier minimizes fracture propagation and actually raises the fracture initiation pressure of the formation. Since ULIA has no polymer component it can be used in temperatures up to 350°F.

  • Micro-fracture formation
  • Permeable matrix formation
  • Fragmental rock formation
  • Shale formation
  • Coal formation

HP sand-bed (20-40 mesh) pressure (1000 psi) with fresh water, invasion length <3.94”, filter cake thickness less than 0.08”. ULIA is also in World Oil Guide to Recommended Oilfield Additives List 2015. 

Product Features

  • PSD optimization resulting in less screen out by shakers.
  • Minimum impact to rheology due to no polymer component.
  • Less formation damage due to acid solubility.
  • Completely compatible with MWD/ LWD tools.
  • Compatible with both water based and synthetic based muds.


ULIA Technical Data

Item Index
Density, ppg 14.16-16.66
Particle size (150 um screen residue), %, max 5.0
Moisture content, WT %,max 8.0
Acid soluble ration, WT %,min 55
AV (5%), mPa.s, Max 3
HP sand-bed (20-40 mesh) pressure, psi, min 1000
Strengthened sand-bed (20-40 mesh) pressure using H2O, psi , min 1000
Formula: 400 ml fresh water + 0.4 g NaOH + 1.6 g Xanthan + 16 g ULIA  

* Filtration test with HPIT (High Pressure Invasion Tester) is recommended to determine the optimum concentration of ULIA.



ULIA Flyer


Vertechs Ultra Low Invasion Additive


1.What are the major components of ULIA?

ULIA is Vertechs’ proprietary low invasion fluid additive, its major components are surface treated inert particles with PSD optimization.

2.What mud systems can ULIA be used in?

OBM, SBM and WBM. ULIA is suitable for most mud types in the market today and respective compatibilities have been previously laboratory tested.

3.What’s the highest working temperature of ULIA?

350 deg F.

4.What impact does ULIA have on production due to permeability loss since the ULIA particles block the near-bore fluid pores and micro-fractures?

Minimal impact. ULIA forms a thin, low permeability and external filter cake on the face of the wellbore which reduces any further invasion of solids or fluid. ULIA is acid soluble and pressure reversible and high permeability rate will be achieved which actually safeguards the permeability of the formation. Test with core sample and specific mud system can be run to verify the performance.

5.What’s the advantage of ULIA over other low invasion fluid additives in today’s market?

  • Minimum impact to rheology due to no polymer component. Traditional low invasion fluid additives require significant polymer components which normally have a severe adverse effect to fluid rheology.
  • Optimized PSD resulting in less screen out by shakers. Testing showed virtually no residue with 100 mesh screens while most low invasion additives lose over 19% or their volume when passing screen mesh sizes between 40 and 100.
  • Less resultant formation damage due to acid solubility and pressure reversibility. 55% (minimum) of the ULIA particles will be soluble after exposure to acid. (15% HCl acid soluble tests have been run, and 55%min PSD optimized acid soluble elastic raw materials are used in the product.) ULIA works like a wedge knocked into the micro-fracture to stop fracture tip propagation and use the rock strength to reinforce the wellbore.

6.What is the recommended concentration for ULIA?

Concentrations range between 3.5ppb-14ppb. Actual effective concentrations will be dependent on fluid type and MW. Additionally, a sand bed test can be used to determine the optimum concentration for each scenario.

7.What is the recommended screen mesh size when using ULIA?

Results of actual residue testing are shown in the table below. Residue while using a 160 mesh screen is less than 10% compared to other similar products which experience over 50% residue at this same mesh size. During field tests while drilling production intervals, satisfactory results have been experienced using 120 mesh screens in WBM and 150 mesh in OBM.

Mesh Size Residue (%)
100 2.0
120 5.0
160 9.9
180 16.0
200 20.2
325 45

8.What is the size of ULIA particles?

The average particle size is 35µ. 10% are smaller than 7µ and 90% smaller than 118µ. 9.Is ULIA toxic? No, it is polymer free and an environmentally friendly additive. It is a mixture of plant derivatives, organic materialand an inert mineral with a fatty acid derivative to treat the particle surface.