Influence of tailor-made TiO2/API bentonite nanocomposite on drilling mud performance: Towards enhanced drilling operations

Abstract

A novel tailor-made TiO2 nanoparticles-bentonite (TNBT) nanocomposite-enhanced drilling mud was tested. The drilling mud showed excellent performance; (i) lubricity was enhanced, (ii) thin and well-intact mud cakes were created, (iii) coating was provided on shale and bentonite plugs, and (iv) clay and shale swelling were mitigated, hence these features ensured a platform for sustainable oil and gas well drilling. The synthesised TNBT nanocomposite followed the one-third bridging rule, i.e., these nanoparticles can bridge nanopore throats in shale pellets and American Petroleum Institute (API) standard bentonite pellets. The tailor-made TNBT nanoparticles were characterized by X-ray diffraction, and scanning electron microscopy. The coefficient of friction and filtrate loss of TNBT-enhanced muds were determined with a lubricity tester, and an API filter press, respectively. Additionally, shale and clay swellings were determined with a linear swell meter. The coefficient of friction was reduced after 0.8 g of TNBT was added to 350 ml drilling mud, resulting in a 35% enhancement in mud lubricity. The new mud also drastically mitigated the swelling in shale and clay when compared to conventional mud. The swelling inhibition was attributed to an increase in the mud viscosity and improved nanopore plugging characteristics, which resulted in less water infiltration. Thus, drilling mud supplemented with the tailor-made TiO2 nanoparticles-bentonite nanocomposite showed superior characteristics and a good potential for field operations.