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  • Increase reservoir drainage and long-term production with large connecting tunnels
  • Save time and money with a flexible, cost-effective stimulation system
  • Minimize your onsite footprint with less surface equipment

  • New and existing oil and gas wells in carbonate reservoirs
  • Openhole completions in carbonate reservoirs
  • Naturally fractured carbonates



Ensure longer-lasting production gains in your carbonate reservoirs with the StimTunnel™ Targeted Acid Placement service from Baker Hughes. By stimulating selected zones, the service creates large, connected tunnels from an openhole main bore. You get an enlarged reservoir inflow area without fracturing the well or using conventional downhole drilling motors, drill bits, or expensive drilling muds—saving time and reducing overall costs.


Targeted stimulation

The StimTunnel Targeted Acid Placement service combines high-pressure jetting and chemical rock acidization to generate a drilling effect that establishes secondary tunnels away from the main bore. An optional memory inclinometer gauge in the tool string tracks tunnel trajectory and orientation for downloading.

The service uses hydrochloric acid to dissolve the carbonate rock, thus eliminating the risks and costs associated with damaging by-products, drill cuttings, or onsite drilling fluid management facilities. Salt, water, and carbon dioxide are the only by-products in the acid reaction, which do not damage the wellbore or formation—unlike common polymers, lost circulation materials, and dispersants used in conventional drilling operations.

The StimTunnel service employs a dual-knuckle tool, conveyed by coiled tubing, to initiate at the main bore of the desired target zone. An array of high-pressure jetting nozzles releases the acid system, efficiently creating a large-diameter tunnel extending 20-100 ft (6-30 m) into the formation of interest. Leak-off acid generates high-density, interconnected, wormhole clusters deep into the formation to improve connectivity and increase production with fewer impairments. This solution also bypasses near-wellbore skin damage and avoids stimulating adjacent water zones while reducing drawdown.

Deploy the service to increase the surface drainage area in your wells, without the need for blenders, frac equipment, or drilling rigs onsite. Minimal surface equipment, including a standard coiled-tubing unit and crew, pumping unit, and acid/mixing tank, are all that is required for an effective operation.

Let’s work together to discover how the StimTunnel Targeted Acid Placement service can help you stimulate your carbonate reservoirs for increased well performance. 


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