The invention provides high-temperature-resistant high-density reversible water-in-oil / oil-in-water
drilling fluid which is composed of the following raw materials in parts by weight: 30-70 parts of an
oil phase, 30-70 parts of an aqueous phase, 2-5 parts of a reversible emulsifier, 1-3 parts of an auxiliary emulsifier, 0-2 parts of organic soil, 1-4 parts of a filtrate
reducer, 0-1 part of an
alkalinity regulator, 0-0.5 part of a
wetting agent, 0-2 parts of an
enhancer and 0-800 parts of weighting materials. The reversible emulsifier is fatty acyl polyamines and derivatives thereof, and has astructural general formula of R1(CH2)m(CONH)n(C6H4)x(NH)y(NH2)zR2; the filtrate
reducer is an amphiphilic filtrate
reducer. The amphiphilic filtrate reducer comprises but is not limited to an amphiphilic
polymer filtrate reducer, a hydrophilic modified
asphalt filtrate reducer and a hydrophobic modified
humic acid filtrate reducer. The compounded auxiliary emulsifier is a high HLB (
Hydrophile-Lipophile Balance) value surfactant. The
drilling fluid disclosed by the invention has directly adjustable density of 0.8-1.8g / cm<3>, and has excellent properties such as rheological property, suspensionstability,
filter cake clearance, filter loss control, environment friendliness and stable reversibility of water-in-
oil emulsion and oil-in-water
emulsion in a range of 100-180 DEG C.