petroleum engineering 406

Petroleum Engineering 406

Lesson 5

Well Control

Read

• Well Control Manual– Chapter 9

• Homework 3– Due Feb. 10, 1999

Content

• Casing Seat Selection– Land and shallow water

• Conventional

• Based on X ppg kick

• Based on X ppg kick and X bbl gain

Content

• Casing Seat Selection– Deep Water

Content

• Casing Seat Selection– Riserless

Land and shallow water

• Plot Pore Pressure and Fracture Gradient curves– Pore pressure from Eaton– Resistivity log

• FP=OB-(OB-FPn)*(Cn/Co)^1.2

– Conductivity• FP=OB-(OB-FPn)*(Ro/Rn)^1.2

– Sonic• FP=OB-(OB-FPn)*(Tn/To)^3

Pore pressure from Eaton

– dc exponent• FP=OB-(OB-FPn)*(dc calculated/dc normal)^1.2

– FP = formation pressure,ppg– OB = overburden stress, ppg– FPn = Normal formation pressure, ppg

Pore pressure from Eaton

– Ro = Shale resistivity from the well log, ohm-meters

– Rn = Shale resistivity from normal trend– Co = Shale conductivity from the well log– Cn = Shale conductivity from the normal line To = Shale travel time from the well log Tn = Shale travel time from the normal line– dc = Corrected d exponent

Fracture Pressure from Eaton

• FG=(OB-FP)*[Poisson’s ratio/(1-Poisson’s ratio)]+FP

Casing Seat Selection - Conventional

Casing seat selection

Standard

0.5 ppg kick

0.5 ppg kick

200’ tallPore Pressure

Fracture Pressure

DataMW 17.9 ppgKick Size 0.5 ppgKick Size 200 feet in annulusSICP 555.36 psi Standard .5 ppg 200 ft

Pore Fracture Pore Fracture Wellbore Wellbore WellboreDepth pressure pressure pressure pressure Press Pressure Pressureft ppg ppg psi psi psi psi psi

0 9 11.4 0 0 0 390 555.361000 9 12.2 468 634.4 930.8 1320.8 1486.168000 9 15.9 3744 6614.4 7446.4 7836.4 8001.768600 15.6 17.6 6976.32 7870.72 8004.88 8394.88 8560.249000 16.4 17.8 7675.2 8330.4 8377.2 8767.2 8932.56

15000 17.8 18.6 13884 14508 13962 14352 14517.36

Deep Water Fracture Pressure

• Eaton’s Gulf Coast Overburden Gradient

Deep Water Fracture Pressure

Deep Water Fracture Pressure

Deep Water Fracture Pressure

OB Gradient below ML

Deep Water Fracture Pressure

Deep Water Casing Seat

Deep Water Casing Seat

Riserless Casing Seats