Schlumberger PublicRotaryRotary(B)ottom (B)ottom (H)ole (H)ole (A)ssembly(A)ssemblyModuleModuleaoag@slb.com2Schlumberger PublicObjectivesDescribe the minimum number of BHA changes needed in:a slant directional well an ! t"#e directional wellDescribe what is meant b":bit side forcefulcrum e$ect#endulum e$ect%lain the e$ect of drill collar sti$ness in BHA designaoag@slb.com'Schlumberger PublicObjectives (2%lain wh" minimi)ing the number of D*+s and stabili)ers is advisable in directional BHA+sDescribe the e$ect of an under gauge near,bit stabili)er in: dro#,o$ BHA+sbuild,u# BHA+show wh" an under gauge second is used in a loc-ed BHA for tangent sectionDescribe the e$ect of hole washout on BHA behavioraoag@slb.com.Schlumberger PublicObjectives ('Describe the e$ect of drilling #arameters have on inclination / direction with each t"#e of BHA%lain wh" fre0uent surve"s is advisable when an 12D tool is available3ive e&am#les of t"#ical BHA designed to build and dro# inclination at various ratesaoag@slb.com4Schlumberger PublicDrilling- Deflection DevicesTools & Techniques to deflect the course of the well in a controlled manner, (overcoming natural tendencies) eg., to:ic!-off, nudge ("uild angle from vertical to a desired direction)Tra#ector$ correction (turn, "uild, dro% to the desired tra#ector$)&idetrac! (deflect the well from it's original course)aoag@slb.com5Schlumberger Public(etting) *sed in soft formations) +ne large "it no,,le oriented to the desired direction) -ear .it &ta"ili,er and lim"er assem"l$) /ash a %oc!et in the formation) &%ud and rotate, wash, until angle is "uilt) 0ontinue "uilding with rotar$ .12) 2,imuth corrections more difficult with 3 inclinationaoag@slb.com6Schlumberger Public+%en 1ole /hi%-stoc!ing) *sed in medium to hard formations) .it, -. &ta". %inned to whi% and conve$ed to "ottom) Tool 4ace oriented) /hi% is wedged on "ottom and %in sheared) *ndersi,ed %ilot hole is drilled) +nl$ one #oint drilled "efore 5++1 the .12) 5ilot hole o%ened u% and %rocess re%eatedaoag@slb.com7Schlumberger Public6789's - D$nadrill) 4irst commercial 5D:) 1$draulic %ower to :ech. %ower driving the .it) &tring !e%t stationar$ - onl$ sliding) .ent su" a"ove motor %rovides side force to the "it) Deflects the hole tra#ector$ - !ic!-off from vertical, sidetrac!, correction run, etc.) ;er$ efficient when com%ared to contem%orar$ deflection devices, (#etting, whi%-stoc!s ..)aoag@slb.com8Schlumberger Public+ther :otor Designs) Tur"ines, Tur"odrills) *sed for im%roving drilling 9's - &teera"le :otors) .end closer to the "it reduces "it offset for equivalent curvature. -? "it offset @ ? com%onent stress- K , 689 l"sAft) this .12 will requireM") Ef the num"er of D0's is limited to 8, how man$ 1/D5 should "e added to the stringM (1/@ I, F7.N l"sAft)aoag@slb.com29Schlumberger PublicBuc-lingr W K I EFBCR sin2 =(in) hole and joint tool pipe between clearance Radial r(lbs/in) air in weight Unit W) (inch inertia of MomentI(unitless) factor Buoyance Modulus s!oung" #(deg) interest of point the at hole the of n Inclinatio (lbs) load buc$ling sinusoidal %ritical &'B%R=======aoag@slb.com22Schlumberger Public&ta"ili,ation) &ta"ili,ed .12 can "e designed to "uild, hold or dro% inclination ) 0ritical elements: )&ta"ili,er gauge)&ta"ili,er %osition)Drill collar +DAweightAmoment of inertia)1ole inclination)/+.,