Introduction of asphalt products with shale inhibitors for drilling fluid

Implementation standard: Q / SH 1500 0056-2013

Role and mechanism:

1: Chemical inhibitor water soluble material content is higher, water soluble part contains a large number of negative ions, negative electric particles through chemical adsorption in clay particles or shale on the edge of positive charge and combined with positive charge, prevent free water into shale, inhibit clay expansion and shale dispersion, a small amount of water insoluble particles by physical adsorption or cover to reduce free water into shale, inhibit shale dispersion and collapse.

2: Physical action Using the softening point characteristics of asphalt, that is, when the softening point of asphalt is close to the temperature of the stratum, the content of water-soluble material of asphalt is low. When drilling into shale formation, the bitumen treatment agent softened under the positive pressure of the wellbore will have plastic flow, embedding and blocking the microcracks in the irregular well wall.Under high temperature and high pressure, asphalt adheres to the well wall to form a compressible filter cake with small permeability to prevent shale surface hydration and infiltration hydration, inhibit shale expansion, dissociation and peeling off, and achieve the purpose of wall protection and protecting the oil and gas layer.