A drilling fluid composition includes an aqueous base fluid, 0.01 to 5 wt. % of polyamine-functionalized activated carbon (AC-PAD), 0.1 to 10 wt. % of a shale material, 0.01 to 2 wt. % of a thickener, 0.1 to 10 wt. % of a fluid loss control additive, 0.01 to 5 wt. % of an adsorbent, and 1 to 20 wt. % of a borehole stabilizer. Each wt. % is based on a total weight of the drilling fluid composition. The AC-PAD is uniformly disposed on surfaces of the shale material. The shale material has an average pore size of 5 to 400 nanometers (nm). A method of preparing the AC-PAD and a method of drilling a subterranean geological formation.

The present invention refers to a composition for water-based foamed fluid with high thermal stability for drilling depressed areas in oil and gas wells, comprising: i) a base fluid or drilling water consisting of fresh water; ii) a stabilizing agent; ii) a viscosifying agent; iv) a filtering reducing agent; v) a clay inhibiting agent; vi) an alkalizing agent and acid gas sequestering agent; vii) a thermal stabilizing agent; and viii) a foaming agent. Also, the present invention refers to a system that uses said composition for fluid and water-based foamed fluid with high thermal stability, the method of preparing the composition for fluid, the method of preparing the fluid and application of the composition and fluid in a water-based foamed fluid system with high thermal stability for drilling depressed or low-pressure areas in oil and gas wells.

A drilling fluid and method for drilling in a coal containing formation with a mixed metal-viscosified drilling fluid including at least 0.05% calcium sulfate.

Methods of stabilizing swellable clays in a subterranean formation and methods of reducing the formation of sludge in a subterranean formation using a biopolymer based cationic surfactant are described. The biopolymer based cationic surfactant includes a quaternary ammonium compound having an alkyl polyglucoside backbone and amino alcohol side chains.

A method for drilling a wellbore into a formation. The method includes: providing a mixed metal-viscosified drilling fluid including at least 1% potassium salt and/or at least 0.05% calcium sulfate; circulating the drilling fluid through the well; and drilling into a formation. An anionic thinner may be added if the clay concentration of the drilling fluid reaches a problematic level to adversely affect pumpability of the fluid.

A method for drilling a wellbore into a formation uses a mixed metal-viscosified drilling fluid including at least 1% potassium salt and/or at least 0.05% calcium sulfate; circulating the drilling fluid through the well; and drilling into a formation. An anionic thinner may be added if the clay concentration of the drilling fluid reaches a problematic level to adversely affect pumpability of the fluid.

A composition for an oil or gas well formation, containing a viscoelastic surfactant; and a modified nanomaterial and a producing method of the composition, and a forming method of the oil or gas well. The modified nanomaterial optionally contains a nanocellulose. The modified nanomaterial optionally has, on its surface, a sulfate group, a sulfite group, a carboxy group, an ethylene oxide chain, an amino group, an ester group, a silane group, a tertiary ammonium group or a mixture thereof.

This disclosure provides compositions suitable as drilling fluids, completion fluids, work-over fluids, or stimulation/fracking fluids, which exhibit shale inhibiting, thermostabilizing, viscosifying, and fluid loss reducing effects when used for these purposes. In some embodiments, this disclosure provides compositions that include a cellulose product comprising the contact product of: at least one cellulosic ether; at least one salt of a polyvalent metal ion; and at least one ligand or a salt of the ligand. The resulting cellulose products are useful in drilling of oil, gas, and other wells.

This invention relates to compositions that have utility, amongst others, in the stabilization of suspension particles or gas bubbles in fluid water-based compositions and/or in conferring shear thinning behavior to such fluid water-based compositions. The inventors have developed parenchymal cellulose based materials, which comprise cell wall derived networks of cellulose based fibers and nanofibrils, can advantageously be used for stabilization of suspended solid particles in fluid water-based compositions. Specific aspects of the invention concern the parenchymal cellulose based materials, their production and their use in fluid water-based compositions, as well as the resulting fluid water-based compositions per se.

This invention relates to water-based well drilling fluids. It has been found that cellulose based particles, which comprise cell wall material and their networks of cellulose based fibers and nanofibrils can be used to produce suspensions having viscosity and rheological properties particularly suitable for use as a drilling fluid. It is assumed that the organization of the cellulose fibrils, as it exists in the parenchymal cell walls, is at least partly retained in the cellulose based particles of the invention, even though part of the pectin and hemicellulose is removed there from. Breaking plant-based pulp down into this kind of cellulose based particles involves fewer and gentler processes than to break the pulp down further into cellulose nanofibrils, and therefore the present cellulose based particles can be produced much faster and at lower cost than completely unraveled cellulose nanofibrils. The well drilling fluids based on the cellulose material of this invention are stable over a wide range of operating temperatures.