Discussion on laboratory evaluation methods in acidizing to Dengying Fm, Gao-Mo block

For the major reservoir characteristics of fracture-cavity in the Sinian Dengying Fm, Gao-Mo block, conventional acidizing effect with short cores which simulates the elimination of reservoir skin damage is hard to meet the requirement of deeply acidizing simulation. For a better guidance to choice acidizing fluid, this paper discusses laboratory evaluation methods of acidizing with long core in Dengying Fm, Gao-Mo block, which includes long core treatment, choice of liquid and choice of experimental parameters. By contrast of laboratory acidizing effect on diverting acid and gelling acid, a conclusion is drawn that diverting acid can't pass through long core, and is effective for high permeability reservoir with increase of permeability by 12.1 times, while gelled acid has good effects on both low and high permeability reservoirs with increase of permeability respectively by 5.6 and 20.0 times. The field application shows that the field effects are consistent with laboratory evaluation, which means evaluation methods of acidizing with long core plays a guidance role in acid fluid choices of Dengying Fm, Gao-Mo block.