Abstract
A new fracturing fluid based on supramolecular complex of associative polymer and wormlike micelle was developed and applied in a gas well in China. The crosslink complex gel was based on weak physical attractive force such as van der waals, hydrogen bonding and electrostatic interaction between associative polymer and wormlike micelle. The fluid contained much less surfactant than that of conventional viscoelastic surfactant. The associative polymer is used at less than 0.25% by weight. The gel is reversible, and has 50% lower formation damage than that of conventional guar. The mixture of the two fluids synergistically enhances the viscosity ten times more than individually combined. The viscosity of fluid can maintain at the test temperature and suspend proppant up under static condition. The dynamic proppant transport test in flow tube also showed good proppant suspension ability. The fluid was simple to prepare with less additives, and formed gel instantly upon mixing in the field. The gel can be completely broken with no residue by an internal breaker. Field application of the new fracturing fluid in a gas well of Sulige basin in China showed the enhancement of gas production over 100%. The fracture height is also well controlled. The fluid also has 20% lower friction pressure than that of guar fluid. Hence, the supramolecular complex gel provides a new fracturing fluid system with less formation damage for fracturing operation.
