DEPARTMENT important functions is the removal of
DEPARTMENT OF PETROLEUMENGINEERINGCOVENANT UNIVERSITYPET327PETROLEUM ENGINEERINGLABORATORYEXPERIMENT :RHEOLOGYGROUP GOLUWATOTAN OLATUNJIDANIEL15CN03290DATE PERFORMED :19-01-2018DATE SUBMITTED :21-01-2018 ABSTRACTIn petroleum engineering there are many functions thatare performed by the drilling fluid inorder to keep the wellbore stable ,on the most important functions is theremoval of cuttings frim the hole .this operation is basically achieved usingthe viscous property of the mud. The rheology is a property of the circulationfluid that have an effect on solids transport. different parameters are tested these includes plastic viscosity(pv),yieldpoint(yp),apparent viscosity (ap) and gel strength .
the information gotten from these parametersare necessary for the control of the mud rheology . this report will determinethe relationship between shear stress and shear rate and examines the gelstrength of a sample of mud using laboratory equipments TABLE OF CONTENT· ABSTRACT · INTRODUCTION · APPARATUS · PROCEDURES · RESULTS AND DISCUSSION · PRECAUTION · CONCLUSIONAND RECOMMENDATION INTRODUCTIONIt is important in drillingengineering that the mud has an optimum rheology property this is to ensurethat the whole is adequately cleaned, the major property responsible for thehole cleaning is the viscous property that will be tested for in thisexperiment. The drilling mud must also be able to suspend cuttings when drilling operations have beentemporarily stopped .there are some factors that affect the rheologicalproperties of the mud, these includes the plastic viscosity which dependslargely on the bulk volume of solids presents and on the viscosity of thesurrounding liquid. yield point and gel strength depend more on the presence of colloidal clays The main instrument thatwould be used in this experiment is· ROTARYVISCOMETER: It determines the shearrate and shear stress of drilling fluids .the speed is easily changed with acontrol knub and shear stress values aredisplayed on a lighted magnified dial for ease of recording .the gel strengthof the mud is shearing stress required to produce a slip –wise movement APPARATUS· ROTARY VISCOMETER· WEIGHING BALANCE· MEASURING CYLINDER· SPATULA · BEAKER· ELECTRIC MIXER· STOP WATCH PROCEDURES (SAMPLE 1)· Using the weighing balance measure 35g of bentonite and add 350ml of water measuredusing measuring cylinder· Mix thoroughly using the electric mixer toachieve a homogenous mixture· Place the splash guard onto the bob shaftwith short table end up towards the bearing· Place the sleeves onto rotor over the bob· Place the test fluid in a simple cup and immerse the rotor sleevesexactly to the fill on the sleeves· Turn the mixture by rotating the speedselector knob · Set the knob to 600rpm allow the reading to stay steady then take thereading· Move the knob to stir, then Set the knob to300rpm ,allow the reading to stay steady then take the reading · Move the knob back to stir ,then set the knobto 60 rpm, allow the reading to stay steady then take there reading· Move the knob back to stir ,then set the knobto 30rpm, allow the reading to stay steady then take the reading· Move the knob back to stir ,the set the knobto gel setting and immediately shut offthe power· As soon as the sleeves stops rotating ,wait10 seconds ,then turn on the power and take the maximum dial reflection· For the 10 minute gel strength ,re stir thefluid and wait 10 minutes before recording the maximum dial deflection PROCEDURE (SAMPLE 2)· Measured 350ml of water in the measuringcylinder· Measure 35g of bentonite using the weighingbalance· Measure 10g of barite using the weighing balance · Repeat procedure 3-11 from sample 1 RESULTS (sample 1) Viscosity (in cp) 51 45 43 40 shear rate (rpm) 600 300 60 30 Gel strength time Viscosity(in cp) 10 sec 52 10 min 65 RESULTS (SAMPLE 2) Viscosity (in cp) 60 54 50 47 shear rate (rpm) 600 300 60 30 GEL STRENGHT time Viscosity(in cp) 10 sec 56 10 min 71 ANALYSIS (SAMPLE 1 )1.
PLASTIC VISCOSITY,PV=600 RPM READING -300 RPMREADING =51 -45=6CP2. YEILD POINT (LB/100FT),YP =300 RPM READING–PV 45-6=393. APPARENT VISCOSITY (CP),AV=600RPM READING/2 51/2=25.
54. GEL STRENGHT ,10.SECONDS(LB/100FT2)=525. GEL STRENGHT,10 MINUTES (LB/100FT2)=65 ANALYSIS(SAMPLE2)1. PLASTIC VISCOSITY (CP), PV =600 RPM READING -300 RPM READING 60-54 =62.
YIELD POINT (LB/100FT2), YP=300 RPM READING –PV =54-6=483. APPARENT VISCOSITY (CP), AV =600RPM READING /2 60/2=304.GEL STRENGHT ,10 SECONDS (LB/100FT2)=565. GEL STRENGHT ,10 MINUTES(LB/100FT2)=71 PRECAUTIONS· I ensured that I avoided the parallax errorwhen taking readings on my stopwatch· I ensured that I removed the sleeve from therotor after use· I ensured that my settings were correct onthe viscometer before taking my readings· I ensured that the platform of my viscometerwas well tightened to avoid any form of movement CONCLUSIONThe rheology of adrilling fluid is an important aspect ofthe drilling process as it determines how the wellbore flows and how itsuspends cuttings, the viscosity, which deals with the resistance to flow, in this report has been determined by theexperiment as well as the gel strength ,other properties that were determinedin this experiment is the yield point, apparent viscosity, plastic viscosity REFERENCESDrilling fluid technology byengr dr.e.
e. okoroDrilling mud manual by engrseteyeobot ifeanyi