Aerated Drilling for Geothermal Wells

 

Known for years, aerated drilling is a technique where certain amount of compressed air or gas is being used in drilling fluid stream to adjust the equivalent circulating density (ECD). This technique is widely used in Geothermal wells that require “unconventional” approaches to reach the target depth.

There are various benefits in utilizing the technology especially as a main tool to combatting losses, summarized as follow

Aerated Drilling

Conventional Drilling

Rate of Penetration (ROP)

Drilling with aerated drilling in fracture formation within many cases shown higher value in ROP. The increment for ROP is caused by the optimized hole cleaning, thus the regrinding phenomenon can be minimized.

Has tendency to have slower ROP due to regrinding effect, especially in present of fracture formation.

Loss Circulation

Aerated drilling has better ability to control fluid loss circulation in fracture formation. Lowering ECD is one of the approaches. In more complex condition, adding ALFA Durrafoam can provide even more ECD reduction as well suspension to hole the cuttings.

Has minimum and limited options in combatting loss circulation, especially in fracture condition.

Annular Velocity

Has improved annular velocity, due to expansion factor of air in the fluid stream.

Constant annular velocity as the function of fluid rate.

Water or Mud consumption

Has lower consumption on water or mud, since the approach is to pump optimum rate of mud as well compressed air.

In many cases, excessive mud or water is pumped to encounter the losses. Thus, the consumption is often very high.

Formation Damage

Has minimum formation damage due to excellent hole cleaning.

Has tendency in plugging the formation, due to insufficient hole cleaning.

Aerated Drilling Equipment Schematic

 

We provide various chemicals to support the aerated drilling needs that vary based on hole conditions.

ALFA Durrafoam

In the presence of massive fractures, time to fill in the gap is critical. ALFA Durrafoam has the ability to bond drilling fluid with compressed air to provide suspension in the form of stiff foam; that durable and agile to mitigate such a challenge.

ALFA Durracorr

Metal surface protection against corrosion is a mandatory to maintain the lifetime, performance, as well the integrity of the goods. ALFA Durracorr can deliver the purpose in form of filming protection against corrosion caused by the presence of the compressed air.