Drilling Fluids

Abstract

Drilling fluids (muds) play a vital role in the drilling of oil and gas wells. These muds are typically complex chemical mixtures formulated to perform a variety of functions under a wide range of down hole temperatures and pressures but yet are nondamaging to the environment and safe for personnel to handle. These fluids are circulated down the hollow drill string and up the annulus, formed by the drill string and the hole to remove formation material dislodged by the bit. The fluids must have sufficient density to offset formation pressures to prevent a blowout and to maintain a stable well bore but be formulated to prevent excessive loss of fluid to permeable formations. Other important functions include lubrication of the drill bit and drill string, collection of information about subsurface formations, and noncorrosivity to surface and down hole equipment. Drilling fluids are composed of liquids (water, petroleum oils, and other organic liquids), dissolved inorganic and organic additives, and suspended, finely divided solids of various types. The article describes drilling fluid classification, properties, materials, testing, economics, and environmental considerations.

Laboratory Study of KCl-Polymer and Soltex Utilization in Preventing Swelling Shale in High Temperature

“…For Yield Point (YP) test results, the Formulation Drilling-Mud I yields 16 lbs/100 ft 2 , the Formulation Drilling-Mud II yields 16 lbs/100 ft 2 , the Formulation Drilling-Mud III yields 20 lbs/100 ft 2 , the Formulation Drilling-Mud IV yields 17 lbs/100 ft 2 , and the Formulation Drilling-Mud V yields 20 lbs/100 ft 2 . Meanwhile, the specification that must be met is 12-21 lbs/100 ft 2 [18] [19]. In these results, all the mud formulations have met the specifications of the drilling-mud standard.…”

“…In mud weight measurements, the Formulation Drilling-Mud I yields 1.09 gr/ml, the Formulation Drilling-Mud II yields 1.11 gr/ml, the Formulation Drilling-Mud III yields 1.11 gr/ml, the Formulation Drilling-Mud IV yields 1.09 gr/ml, and the Formulation Drilling-Mud V yields 1.11 gr/ml. Meanwhile, the required specification (Rheology Standard for Drilling Mud at depths of 6000-9000 ft) is 1.09-1.16 gr/mL [18] [19]. From the test results, it can be seen that all the results are within the specification standard that can be categorized as good mud.…”

“…In Plastic Viscosity (PV) measurements, the Formulation Drilling-Mud I yields 15 cp, the Formulation Drilling-Mud II yields 18 cp, the Formulation Drilling-Mud III yields 10 cp, the Formulation Drilling-Mud IV yields 19 cp, and the Formulation Drilling-Mud V yields 20 cp. Meanwhile, the specification must be met (< 20 cp) [18] [19]. In these results, all the mud formulations have met the specifications of the drilling-mud standard.…”

“…At Gel Strength measurement of 10 minutes, the required drilling-mud specification is 6-14 lbs/100 ft 2 [18] [19]. The Formulation Drilling-Mud I yields 6 lbs/100 ft 2 , the Formulation Drilling-Mud II yields 7 lbs/100 ft 2 , the Formulation Drilling-Mud III yields 8 lbs/100 ft 2 , the Formulation Drilling-Mud IV yields 10 lbs/100 ft 2 , and the Formulation Drilling-Mud V yields 10 lbs/100 ft 2 .…”

“…At the K + measurement, all the formulations yield 36216 mg/l. Meanwhile, the specification of ≥ 33000 mg/l [18] [19]. From the results, all formulations of drilling mud have fulfilled the specification to prevent shale development.…”