The particular foamed cement formulation by acid for oil/gas wells cementing jobs: an experimental approach

Abstract

In this paper, new foamed cement has been formulated and designed for oil-gas wells liner and casing cementing jobs. Ultra-lightweight cements such as foamed cements are appropriate for formation damage prevention in fractured and depleted reservoirs. Current foamed cements have been prepared at high shear rates by boric acid and HA-(SLES) as a foaming agent. Different tests such as density, rheology, free water, settling, thickening time, compressive strength, fluid loss, porosity, permeability, microscopic photography and CT scanning are conducted for each sample. The results illustrate that the designed foamed cement (FBJ) has one of the lowest densities (1200 kg/m3) between drilling-cements, the compressive strength of 8963 kPa, thickening time near 3 hours. Also, its rheology becomes better in HPHT conditions. The porous media of FBJ's set-cement is not interconnected and this has been proved by porosity, permeability, microscopic photography and CT scan tests. Helium porosimeter demonstrated that FBJ's porosity is more than 73% and CT scan image processing proved that 28% of FBJ is the matrix. Moreover, the cement permeameter indicated that the permeability of FBJ's porous media is just 0.0109 mD. All of these experimental analyses show that FBJ has acceptable properties for oil-gas wells cementing jobs.