Formation Acid Treatment

Region LLC considerably experienced in both hydrochloric treatment of Carboniferous reservoirs and mud-acid treatment in Terrigenous reservoirs.

 During well drilling or due to its continuous operation the bottom-hole formation zone is usually contaminated, resulting in additional filtration resistance in the near-wellbore zone (skin-effect). Such resistance leads to reduce of real flow rate by ten times against the potential one. In this case Region’s specialists recommend formation acid treatment, which may help to eliminate additional filtration resistance and clean up the bottom-hole formation zone.

Success of acid treatment is based upon two components:

1. Correct formulation of the applied acid compositions.
2. Delivery of acid solutions to the least responsive parts of the layer.

In Region company hydrochloric compositions are custom-designed for every individual well, giving due consideration to physicochemical reservoir properties as well as produced fluids and well design. Drill cuttings solvability in the suggested acid agents is analyzed practically in all cases and acids compatibility with formation fluids is subject to verification.

Acid compositions used by our company include the following:

• Inhibitors, ensuring downhole equipment from corrosion;
• Intersolubilizing agents, blocking formation of hard emulsions in the layer;
• Complexing agents, preventing formation of water-insoluble salts;
• Surfactants,  facilitating acid solution resultant returns;
• Retarders, ensuring acid deep penetration which means deeper formation treatment.

If necessary, our experts also use friction reducing agents, demulsifiers, shale stabilizers.
Apart from correct formulation, delivery of acid composition to the least responsive interlayers is ultimately critical for successful acid treatment.  It is well known that a layer, having one highly permeable sublayer, can receive up to 99% of the total volume of mud, whereas the rest parts of productive horizon will remain untreated.

To ensure uniform distribution of acid through the whole thickness of layer “Region” company applies the following technologies:

1. Use of coiled tubing unit for the uniform distribution of acid through the whole perforation interval;
2. Use of chemical and mechanical deflecting tools to block highly permeable parts of the layer;
3. Application of foam-acid fluids.

Our company is empowered with full set of equipment for both hydrochloric treatment and mud-acid treatment as well as unmatched in Ukraine fleet of acid-resistive vessels of more than 600 m³ overall capacity. Specialists of “Region” LLC are known to perform unique hydrochloric treatment operations, having delivered 200 m³ of acid composition into the layer, using coiled tubing.