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Presentation Topic :Drilling Fluids Presented to: Dr. Nazir Ahmad Presented By: Muhammad Wajid Manzoor Roll no . 09 Institute of Geology University of the Punjab Lahore.

contents Definition History Types of drilling fluids Functions of drilling fluids Disadvantages References

DefinitionA circulating fluid used in rotary drilling to perform any or all of the various functions required in a drilling operation is known as drilling fluid.

History The history of drilling fluid is separated into three periods :1. The early period from ancient times up to the completion of the spindle top well in 1901.(Spindletopis asalt domeoil fieldlocated in the southern portion ofBeaumont, Texasin the United State. 2. The period from 1901 to 1928 , When engineers were conducting test on drilling mud to meet specific drilling needs. 3.The period extend from 1928 to the present.

History In 1845 Fauvelle Successfully drilled a well in France by using water flushed set off tools .Then he drilled more wells by using this tool.In 1880 Chapman mixed the water and mud to make the muddy fluid and this was the begging of mud engineering .In Oct 1900, Curt Hamil mixed a muddy fluid and pumped into the hole which promptly sealed off the quicksand and solved the problem.

Types of Drilling fluids The various types of fluid generally fall into a few broad categories. The three key factors that drive decisions about the type of drilling fluid selected for a specific well are:1. Cost 2.Technical Performance 3.Environmental impact

Types of Drilling fluids The various types of fluid generally fall into a few broad categories:Water-based fluidsOil-based fluids Synthetic-based drilling fluids All-oil fluids Pneumatic-drilling fluids

Types of Drilling fluids Water-based Fluids:

Water-based fluids (WBFs) are used to drill approximately 80% of all wells.The base fluid may be fresh water, seawater (Calcium chloride, Calcium bromide, Zinc bromide) , brine.

Types of Drilling fluids 2. Oil-based Fluids: Oil-based systems were developed and introduced in the 1960s to help address several drilling problems:Clay formation that react, swell, or slough after exposure to WBFsIncreasing downhole temperaturesContaminantsStuck pipe and torque and drag

Types of Drilling fluids Oil-based fluids (OBFs) in use today are formulated with diesel, mineral oil, or low-toxicity linear olefins and paraffin's.Barite is used to increase system density, and specially-treated organophilic bentonite is the primary viscosifier in most oil-based systems.

Types of Drilling fluids 3. Synthetic-based drilling fluids:Synthetic-based fluids were developed out of an increasing desire to reduce the environmental impact of offshore drilling operations, but without sacrificing the cost-effectiveness of oil-based systems.SBFs can be used to:Maximize rate of penetrations (ROPs)Increase lubricity in directional and horizontal wellsMinimize wellbore-stability problems, such as those caused by reactive shale

Types of Drilling fluids 4. All-oil fluid:Normally, the high-salinity water phase of an invert-emulsion fluid helps to stabilize reactive shale and prevent swelling. By eliminating the water phase, the all-oil drilling fluid can preserve shale stability throughout the interval

Types of Drilling fluids 5. Pneumatic-drilling fluids :Compressed air or gas can be used in place of drilling fluid to circulate cuttings out of the wellbore. Pneumatic fluids fall into one of three categories:Air or gas onlyAerated fluidFoamPneumatic-drilling operations require specialized equipment to help ensure safe management of the cuttings and formation fluids that return to surface, as well as tanks, compressors, lines, and valves associated with the gas used for drilling or aerating the drilling fluid or foam.

Functions of drilling fluids

Drilling fluids perform many functions during drilling process , some of these are given below :1. It transport the drilled cuttings and carrying to the surface .2. It transport the cuttings and carrying in annulus when circulation is stopped. 3. It controls the subsurface pressure .4. Support the walls of borehole .5. Used to produced induced fracturing .

Functions of drilling fluids6. It helps in suspension of weight of drill string and casing .7. It deliver hydraulic energy upon formation beneath the bit .8. It seals off permeable formation by creating a wall cake .9. It prevents sloughing or erosion of formation in an open hole.It cools and lubricate the bitt and drill string.It provides a suitable media for running wireline logs.Circulates the cavings when occur .Permits fast drilling by cleaning the hole .

Disadvantages

There are following problems or disadvantages related to drilling fluids which are given below :Drilling fluids damages the subsurface formation specially to producing formation by its velocity and weight .Corrosion of drill string and casing can be occur if certain chemical are added in in the fluid.It can also slow down rate of penetration (ROP) when heavy mud is used .Loss of circulation is also a major problem associated with mud .

Disadvantages

6. Sticking of drill string against the walls of bore hole .7. Drilling mud also damage the drilling equipment's.

References

Oilfield Market Report 2004. Spears & Assoc. Inc., Tulsa, Oklahoma, www.spearsresearch.com.Annual Report of the OSPAR Commission, 20002001, 30. 2001. London: OSPAR Commission.fckLRG. V. Chilingarian & P. Vorabutr (1983)Drilling and Drilling FluidsDCS Shale Shaker SUPPLIERThe Drilling Fluids cleaning system