with Reformulated Polymer Gel and TDI’s New Gel Unit
Since plugging or sealing over 100 miles
of in-mine borehole and surface CBM Well coal laterals,
including sidetracks, with over 500,000 gallons of
Concrete Construction Materials’ (CCM) original
formulation of poly acrylimide gel culminating in the safe
mine-through of the gelled boreholes, the original gel
formulation was found to be ineffective when used to gel
several surface CBM well coal laterals when mined into.
Chemical analysis of the fluid found in the mined into coal laterals determined that the high concentration Total Dissolved Solids (TDS) (> 20,000 ppm) and the volume of water with high concentration of TDS prevented the gel mixture injected into the coal laterals to cure.
Consequently, CCM reformulated the polymer gel to be TDS “proof” increasing the concentration of polymer and other chemicals in the gel mixture. In addition, TDI redesigned and fabricated a new gel mixing and pumping unit that can mix and circulate 2,000 gallons of gel ingredients while simultaneously pumping 180 gallons per minute of mixed gel from another tank.
Protocol was established to gel an in-mine or surface CBM wells coal laterals treating every borehole or lateral to be gelled as “site specific or unique.” Using the new gel unit to mix and pump 122,000 gallons of reformulated gel, five (5) in-mine boreholes and four CBM wells were gelled and subsequently mined into by the continuous miner or longwall face without incident. The quantity of gel pumped is almost two times the calculated volume of the boreholes, including sidetracks. The gel effectively squeezes into the fracture system of the coal displacing gas and water. Lastly, with an affinity to attach itself to everything, except for itself, the gel adhered to the inner wall of the borehole providing an impenetrable skin, minimizing gas and water migrating back into the borehole as evidenced by mining into the boreholes.