1. In a development well, the 8 3/4-in hole was drilled to 9,000 ft. It is...

 

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1. In a development well, the 8 3/4-in hole was drilled to 9,000 ft. It is intended to seal the wellbore using the 7-in casing. The next hole section is to be drilled using 5 7/8-in drill bit to the measured depth of 13,000 ft. This hole will be completed with 5 7/8-in casing. The drilling mud weight of 12 ppg will used to drill this hole section. Table Q1 shows the casing size selection. It is noted that the pore pressure gradient at the next section total depth is 0.4 psi/ ft. Casing Grade K-55/26-LTC M-65/26-LTC M-65/29-LTC M-65/32-LTC Weight lb/ft 26 26 29 32 OD in 7 7 7 Table Q1 ID in 6.276 6.276 6.184 6.094 Burst psi 4979 5878 6628 7358 Collapse psi 4329 4809 6098 7358 Tensile Strength 1000 lb 401 428 492 554 a) Deduce with reasons the most practical and economical 5-in casing nominal weight and its grade to be used for this well based on Table Q1. It is noted that the API design factors are: Tension, NT 1.8, Burst, Ni= 1.1, Collapse Nc = 1.2. b) To safely drill the 5 7/8-in hole section considering 13 ppg mud weight, i) compute the minimum mud weight required. ii) show that the mud weight is suitable for drilling operations. [7 marks] [2 marks] [6 marks] c) It is intended to design a well to produce from three pay-zones with a 9 5/8-in casing string and with a clearance of 0.1-in. Sketch with label the suitable tubing configurations to be used for this well. [7 marks] 1. In a development well, the 8 3/4-in hole was drilled to 9,000 ft. It is intended to seal the wellbore using the 7-in casing. The next hole section is to be drilled using 5 7/8-in drill bit to the measured depth of 13,000 ft. This hole will be completed with 5 7/8-in casing. The drilling mud weight of 12 ppg will used to drill this hole section. Table Q1 shows the casing size selection. It is noted that the pore pressure gradient at the next section total depth is 0.4 psi/ ft. Casing Grade K-55/26-LTC M-65/26-LTC M-65/29-LTC M-65/32-LTC Weight lb/ft 26 26 29 32 OD in 7 7 7 Table Q1 ID in 6.276 6.276 6.184 6.094 Burst psi 4979 5878 6628 7358 Collapse psi 4329 4809 6098 7358 Tensile Strength 1000 lb 401 428 492 554 a) Deduce with reasons the most practical and economical 5-in casing nominal weight and its grade to be used for this well based on Table Q1. It is noted that the API design factors are: Tension, NT 1.8, Burst, Ni= 1.1, Collapse Nc = 1.2. b) To safely drill the 5 7/8-in hole section considering 13 ppg mud weight, i) compute the minimum mud weight required. ii) show that the mud weight is suitable for drilling operations. [7 marks] [2 marks] [6 marks] c) It is intended to design a well to produce from three pay-zones with a 9 5/8-in casing string and with a clearance of 0.1-in. Sketch with label the suitable tubing configurations to be used for this well. [7 marks]

Answer rating: 100% (QA)

SOLUTION a To determine the most practical and economical 5in casing nominal weight and grade we need to consider the API design factors and compare the burst and collapse ratings of the available cas... View the full answer