Impervious synthetic layered silicates coating to restrict the swelling of clay‐rich shales
Hasmukh A. Patel, Ashok Santra
Abstract
Abstract An incremental demand towards the use of water‐based fluids for drilling oil and gas wells has generated numerous challenges in the field of shale inhibition characteristics. One of the major problems associated with the use of water‐based drilling fluids is the interaction of water with clay‐rich shales that leads to hydration and swelling of reactive clays. We have developed functionalized nanoplatelets composed of amine functionalities anchored on the nanometre‐thick magnesium silicates (LMS‐NH 2 ). A facile synthetic approach was employed to synthesize lab‐scale quantity of LMS‐NH 2 through combination of sol–gel and precipitation techniques. The structural characterization was conducted using powder X‐ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis to evaluate generation of anticipated LMS‐NH 2 . Shale stabilization characteristics of LMS‐NH 2 were tested and compared with other commercial shale inhibitors. Clay swelling and clay dispersion tests were performed to demonstrate the effectiveness of the impermeable coating of nano‐platelets on to the clay‐rich shales. The LMS‐NH 2 demonstrated 87% recovery of swellable shales after dispersion tests. The microscopic study conducted on shales revealed the formation of inorganic film, which provide impervious coating to protect the water‐susceptible clays. The linear swelling measurements were also performed to understand the effectiveness of LMS‐NH 2 over 72 h. LMS‐NH 2 demonstrated linear swelling of 31.7% when compared with drilling fluid without shale inhibitor. The newly developed inhibitor in the current study has outperformed conventional shale inhibitors (a 18.7% reduction in linear swelling), wherein the presence of inorganic constituents aids stronger film formation compared to solely organic inhibitors.