Control Placement of Scale Inhibitors in the Formation With Stable Ca-DTPMP Nanoparticle Suspension and its Transport Porous Media

Abstract

Abstract Diethylenetriaminepentatakis(methylene phosphonic acid) (DTPMP) is commonly used in oilfield for scale inhibition. In this study, Ca-DTPMP submicron-sized particles were prepared directly by chemical precipitation with the assistance of phosphino-polycarboxylic acid (PPCA). The influences of adsorbed PPCA, KCl concentration and sonication on the transport and deposition kinetics of Ca-DTPMP particle suspensions in calcite and sandstone matrix were investigated. Adsorption of PPCA to Ca-DTPMP particles increases their negative surface charge and decreases particles deposition in a porous media. The mobility of PPCA-coated Ca-DTPMP particles decreases with increasing KCl concentrations. Using sonication treatments the mobility of Ca-DTPMP particles at high KCl concentration in porous media increased significantly. The retention and long term flow back performance of Ca-DTPMP particles were tested in Frio sandstone columns after 18 hours shut-in time to allow deposition. The results show that enhanced retention of Ca-DTPMP particles and slow dissolution of DTPMP are highly advantageous in slowing the phosphonate release from porous media, and ensuring successful inhibitor treatments in oil fields.