Bentonite (or other clay) water-based drilling fluids incorporating functionalized cellulose nanocrystals are disclosed. Cellulose nanocrystals are modified with tailored surface charges or tailored levels of salt-tolerant polymer grafting, and combined with bentonite (or other clay) nanoplatelets in an aqueous suspension. Thermal performance of drilling fluids can also be enhanced by surface grafting of thermally functional polymers onto cellulose nanocrystals.

A trimodal hybrid particle mix loss prevention material (LPM) is provided. The trimodal hybrid particle mix LPM includes date palm seed particles produced from date palm seeds, scrap tire particles produced from scrap tires, and date tree pruning waste particles produced from date tree pruning waste. The LCM may include date palm seed particles in the range of about 40 wt % to about 50%, scrap tire particles in the range of about 30 wt % to about 40 wt %, and date tree pruning waste particles in the range of about 15 wt % to about 25 wt %. Methods of loss prevention and manufacture of a trimodal hybrid particle mix LPM are also provided.

The present invention relates to the field of drilling fluids, and discloses a drilling fluid that can inhibit surface hydration of clay and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, an intercalation inhibitor, a tackifier, a flow pattern regulator, a filtrate reducer, a lubricant, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 2-9 parts by weight, the content of the intercalation inhibitor is 0.3-4 parts by weight, the content of the tackifier is 1-10 parts by weight, the content of the flow pattern regulator is 0.8-7 parts by weight, the content of the filtrate reducer is 1-8 parts by weight, the content of the lubricant is 0.5-4 parts by weight, and the content of the weighting agent is 12-60 parts by weight; the intercalation inhibitor prepared in the present invention can effectively control the degree of surface hydration of clay and thereby greatly improve the inhibition performance of the drilling fluid system by virtue of adsorption, intercalation, and ion exchange effects, etc. attained by the adsorptive groups that have specific functions in the intercalation inhibitor, when the intercalation inhibitor is intercalated in a form of a single spread layer between grain layers of clay minerals.

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.

A drilling fluid composition includes an aqueous base fluid, 0.01 to 10 wt. % of a date palm leaves extract (DPLE), 1 to 10 wt. % of clay particles, and 0.01 to 1 wt. % of a base, where each wt. % based on a total weight of the drilling fluid composition. The DPLE is homogenously disposed on surfaces of the clay particles. The clay particles disposed with the DPLE are present in the drilling fluid composition in the form of a composite. A pellet made from the clay particles treated with the DPLE has a swelling value at least 75% less than a swelling value of the pellet in an aqueous composition that does not contain the DLPE. A method of making the drilling fluid composition.

A drilling fluid composition includes an aqueous base fluid, 0.01 to 10 wt. % of a date palm leaves extract (DPLE), 1 to 10 wt. % of clay particles, and 0.01 to 1 wt. % of a base, where each wt. % based on a total weight of the drilling fluid composition. The DPLE is homogenously disposed on surfaces of the clay particles. The clay particles disposed with the DPLE are present in the drilling fluid composition in the form of a composite. A pellet made from the clay particles treated with the DPLE has a swelling value at least 75% less than a swelling value of the pellet in an aqueous composition that does not contain the DLPE. A method of making the drilling fluid composition.

A drilling fluid composition includes an aqueous base fluid, 0.01 to 10 wt. % of a date palm leaves extract (DPLE), 1 to 10 wt. % of clay particles, and 0.01 to 1 wt. % of a base, where each wt. % based on a total weight of the drilling fluid composition. The DPLE is homogenously disposed on surfaces of the clay particles. The clay particles disposed with the DPLE are present in the drilling fluid composition in the form of a composite. A pellet made from the clay particles treated with the DPLE has a swelling value at least 75% less than a swelling value of the pellet in an aqueous composition that does not contain the DLPE. A method of making the drilling fluid composition.

A method includes adding a clay to water to form a suspension of clay in water, the clay including pieces of clay having an average diameter of at least 2 m; adding a dispersant to the suspension of clay in water to form a drilling fluid; and injecting the drilling fluid into a well. In the drilling fluid, the dispersant interacts with the clay to form nanoscale particles of clay having an average diameter of less than 500 nm.

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.

A drilling fluid composition includes an aqueous base fluid, 0.01 to 10 wt. % of a date palm leaves extract (DPLE), 1 to 10 wt. % of clay particles, and 0.01 to 1 wt. % of a base, where each wt. % based on a total weight of the drilling fluid composition. The DPLE is homogenously disposed on surfaces of the clay particles. The clay particles disposed with the DPLE are present in the drilling fluid composition in the form of a composite. A pellet made from the clay particles treated with the DPLE has a swelling value at least 75% less than a swelling value of the pellet in an aqueous composition that does not contain the DLPE. A method of making the drilling fluid composition.