Evaluation of nancompsite polypropylene-nanosilica as fluid loss control material for high pressure high temperature condition

Abstract

A potential additive for water-based mud which is the newly synthesized nanocomposite polypropylene based nanosilica (PP-SiO2 NC) has showed promising results in reducing shale swelling, enhancing cutting transport efficiency and reducing the fluid loss, but at low temperature only. Therefore, in this study, the efficiency of filtration loss was carried out for high temperature high pressure (HPHT) and its performance was compared to the commercial filtration agent Polyanionic Cellulose (PAC) at the simulated reservoir conditions. 7 samples of mud were prepared from 0.5 to 1.5 gram of (PP – SiO2 NC) PAC mud. The effect of temperature on the critical rheological properties such as plastic viscosity (PV), yield point (YP), gel strength (GS) and pH at the above concentrations were evaluated. Then, the effect of (PP – SiO2 NC) on filtration loss was evaluated at following conditions. First, at 100 psi as constant pressure and ambient temperature using the standard American Petroleum Institute (API) filtration method. The second filtrate loss measurement is at high pressure high temperature (HPHT) conditions. For HPHT measurement, it was tested at 250 oF temperature while the pressure was 500psi as differential pressure. Addition of both PAC and PP – SiO2 NC before ageing improved the properties of the WBM. There are no much variation between the rheology PV,YP and GS of PAC and PP – SiO2 NC . The PV of the WBM with PP – SiO2 NC has an optimum value at 1g concentration while the addition of PAC into WBM increases the PV with increasing concentration. After ageing PV for both the PAC and PP – SiO2 NC with a concentration of 1.5g and 1g respectively increased by 53.8 % and the YP of PAC increased by 25%, while for the PP – SiO2 NC mud improved by 40% compared to basic mud. The lower API filtration loss and mud cake thickness were obtained through adding 1.5g PAC .In the other hand at HPHT test showed a prospective reduction in the fluid loss and the best result was achieved by adding 1.5 g of PP-SiO2 NC 67.7% compared to basic mud. In addition, at HPHT It was observed that filter cake characteristic was improved by obtained thin and low permeability mud cake observation made indicated that the filter cake thickness and permeability for the samples with different concentrations of PP – SiO2 NC were lower than that of PAC the lowest values of mud cake thickness and permeability 50% and 85.2% respectively through adding 1.5g PP-SiO2 NC compared to basic fluid.