Home » Casing » Conductor Casing Pipe Specs, Installation For Oil & Gas

Conductor Casing Pipe Specs, Installation For Oil & Gas

The conductor pipe runs from the seafloor/surface to relatively shallow depths providing a conduit to allow circulation of drilling fluid as well as case off unconsolidated formations. It is the first string that is used to support well control equipment, typically a drilling diverter. A common size for the conductor casing pipe is 24″, 26″ or 30″ and it is set from 40m to 5OO m below the seafloor/surface. Here we will discuss in detail conductor casing pipe specifications, connectors, installation, hammering, and running operations in oil and gas wells. We shall also provide conductor pipes specifications sheets

Conductor casing Pipe supports the wellhead, the weight of all subsequent casing strings and tubing in many wells, but there are many other wells where the conductor plays no role as a structural member. It maintains borehole integrity through the usually soft surface formations. It seldom gives us any pressure control though because the formations in which it is set often have very little strength so its role in maintaining borehole integrity is relatively short-lived and severely limited.

As conductor casing pipe is considered one of the Types Of Casing, so its specifications are the same as casing specifications.

Oil and Gas Conductor Casing Pipe Specifications Tables

Below we have gathered some of the Conductor casing pipe specs tables that you can use from oil and gas NOV & Varcogray

XL Systems–National Oilwell Varco—XLC-S

Type: Integral, flush Seal: Metal-to-metal

ODWeightID (drift), in.wall thicknessConnection OD, in.Casing wall critical cross-sectional Connection critical cross-sectional Tensile
efficiency, % 
 Compression
efficiency, % 
L-80 Joint strength, kips L-80 Yield torque ft-lbP-110 Joint strength kipsP-110 Yield torque  ft-lbQ-125 Joint  strength kipsQ-125 Yield torque   ft-lb
26202.324.50.752659.49439.42766663,154233,0004,337320,0004,928364,000
262672412678.5455.09770704,408319,0006,061439,0006,887498,000
26330.423.51.252697.19375.51978786,042429,0008,307590,0009,440670,000
26392.5231.526115.45491.11879797,289508,00010,023698,00011,390793,000
30234.328.50.753068.91945.6166663,649313,0005,017430,0005,701489,000
30309.72813091.10663.80570705,104431,0007,019592,0007,976673,000
30383.827.51.2530112.90187.58378787,007581,0009,634799,00010,948908,000
30456.6271.530134.303105.79679798,464691,00011,638950,00013,2251,079,000
3052826.51.7530155.312124.07980809,926797,00013,6491,095,00015,5101,245,000
30598.126230175.929141.912818111,353896,00015,6101,232,00017,7391,400,000
32250.330.50.753273.63148.70166663,896358,0005,357492,0006,088559,000
32331.13013297.38968.15970705,453493,0007,497677,0008,520770,000
32410.529.51.2532120.75593.61578787,489666,00010,298916,00011,7021,041,000
32488.6291.532143.728113.13579799,051793,00012,4451,090,00014,1421,238,000
32565.428.51.7532166.308132.75808010,620916,00014,6031,259,00016,5941,431,000
32640.828232188.496151.902818112,1521,032,00016,7091,419,00018,9881,612,000
34266.332.50.753478.34351.79266664,143405,0005,697557,0006,474633,000
34352.432134103.67372.51470705,801559,0007,977768,0009,064873,000
34437.231.51.2534128.60999.64677777,972757,00010,9611,041,00012,4561,183,000
34520.7311.534153.153120.47379799,638902,00013,2521,240,00015,0591,409,000
34602.830.51.7534177.304141.421808011,3141,043,00015,5561,434,00017,6781,630,000
34683.530234201.062161.893818112,9511,177,00017,8081,618,00020,2371,839,000
36282.434.50.753683.05654.88466664,391456,0006,037627,0006,861712,000
36373.834136109.95676.86870706,149629,0008,455865,0009,609983,000
36463.933.51.2536136.463105.67877778,454853,00011,6251,173,00013,2101,333,000
36552.7331.536162.577127.812797910,2251,018,00014,0591,400,00015,9771,590,000
36640.132.51.7536188.299150.092808012,0071,179,00016,5101,621,00018,7621,842,000
36726.232236213.628171.883808013,7511,332,00018,9071,831,00021,4852,081,000
38298.436.50.753887.76857.97566664,638509,0006,377700,0007,247796,000
38395.236138116.23981.22270706,498704,0008,934968,00010,1531,100,000
38490.635.51.2538144.317111.7177778,937956,00012,2881,314,00013,9641,493,000
38584.7351.538172.002135.151797910,8121,141,00014,8671,569,00016,8941,783,000
38677.534.51.7538199.295158.763808012,7011,323,00017,4641,819,00019,8452,067,000
3876934238226.195181.873808014,5501,496,00020,0062,057,00022,7342,337,000
40314.438.50.754092.48161.06666664,885566,0006,717778,0007,633884,000
40416.538140122.52285.57670706,846783,0009,4131,076,00010,6971,223,000
40517.337.51.2540152.171117.74277779,4191,064,00012,9521,463,00014,7181,662,000
40616.8371.540181.427142.49797911,3991,271,00015,6741,748,00017,8111,987,000
40714.936.51.7540210.29167.433808013,3951,475,00018,4182,029,00020,9292,305,000
40811.736240238.761191.863808015,3491,670,00021,1052,296,00023,9832,609,000
40907.135.52.2540266.839221.51838317,7211,904,00024,3662,618,00027,6892,975,000
42330.440.50.754297.19364.15866665,133625,0007,057860,0008,020977,000
42437.940142128.80589.93170707,194866,0009,8921,191,00011,2411,353,000
4254439.51.2542160.025123.77477779,9021,178,00013,6151,619,00015,4721,840,000
42648.8391.542190.852149.828797911,9861,409,00016,4811,937,00018,7292,201,000
42752.338.51.7542221.286176.104808014,0881,636,00019,3712,250,00022,0132,557,000
42854.438242251.327201.854808016,1481,853,00022,2042,548,00025,2322,896,000
42955.237.52.2542280.976223.36797917,8692,027,00024,5702,787,00027,9203,167,000
44346.442.50.7544101.90567.24966665,380688,0007,397945,0008,4061,074,000
44459.242144135.08894.28570707,543953,00010,3711,310,00011,7861,489,000
44570.741.51.2544167.879129.806777710,3841,297,00014,2791,784,00016,2262,027,000
44680.9411.544200.277157.167787812,5731,553,00017,2882,135,00019,6462,427,000
44789.740.51.7544232.282184.775808014,7821,805,00020,3252,482,00023,0972,821,000
44897.140244263.894211.844808016,9482,046,00023,3032,814,00026,4813,198,000
441003.339.52.2544295.113245.21838319,6172,342,00026,9733,221,00030,6513,660,000
46362.544.50.7546106.61870.3466665,627753,0007,7371,035,0008,7931,176,000
46480.644146141.37298.63970707,8911,044,00010,8501,436,00012,3301,632,000
46597.443.51.2546175.733135.838777710,8671,423,00014,9421,956,00016,9802,223,000
46712.9431.546209.701164.506787813,1601,705,00018,0962,344,00020,5632,663,000
4682742.51.7546243.277193.446808015,4761,983,00021,2792,726,00024,1813,098,000
46939.842246276.46221.834808017,7472,249,00024,4023,093,00027,7293,514,000
461051.341.52.2546309.251257.13838320,5702,579,00028,2843,546,00032,1414,030,000
461161.5412.546341.648291.593858523,3272,893,00032,0753,978,00036,4494,521,000
48378.546.50.7548111.3373.43266665,875821,0008,0781,129,0009,1791,283,000
4850246148147.655102.99470708,2401,140,00011,3291,568,00012,8741,781,000
48624.145.51.2548183.587141.87777711,3501,554,00015,6062,137,00017,7342,428,000
48744.9451.548219.126171.845787813,7481,863,00018,9032,562,00021,4812,911,000
48864.444.51.7548254.273202.117797916,1692,169,00022,2332,982,00025,2653,388,000
48982.644248289.027231.825808018,5462,462,00025,5013,385,00028,9783,846,000
481099.443.52.2548323.388268.779838321,5022,825,00029,5663,884,00033,5974,413,000

XL Systems–National Oilwell Varco—XLF

Type: Integral, flush Seal: Metal-to-metal

ODWeightID (drift), in.wall thicknessConnection OD, in.Casing wall critical cross-sectional Connection critical cross-sectional Tensile
efficiency, % 
 Compression
efficiency, % 
L-80 Joint strength, kips L-80 Yield torque ft-lbP-110 Joint strength kipsP-110 Yield torque  ft-lbQ-125 Joint  strength kipsQ-125 Yield torque   ft-lb+O78:O101O78:O1O78:O105
20104.1190.52030.63115.87952521,27073,0001,747100,0001,985113,000
20129.318.750.6252038.04320.08253531,60791,0002,209125,0002,510142,000
20131.318.730.6352038.63120.08252521,60791,0002,209125,0002,510142,000
20154.218.50.752045.35725.07655552,006112,0002,758154,0003,135175,000
20166.418.3760.8122048.94825.07651512,006111,0002,758153,0003,135174,000
20202.91812059.6938.45564643,076167,0004,230230,0004,807261,000
20250.317.51.252073.63150.99469694,080216,0005,609298,0006,374338,000
22114.8210.52233.77217.48852521,39988,0001,924122,0002,186138,000
22142.720.750.6252241.9722.12453531,770111,0002,434152,0002,766173,000
22170.220.50.752250.06927.63655552,211137,0003,040188,0003,455213,000
22224.32012265.97342.42664643,394205,0004,667282,0005,303320,000
2227719.51.252281.48556.31969694,506266,0006,195366,0007,040416,000
24125.5230.52436.91419.09652521,528106,0002,101145,0002,387165,000
2415622.750.6252445.89724.16553531,933132,0002,658182,0003,021207,000
24186.222.50.752454.78230.19655552,416164,0003,322225,0003,775256,000
24245.62212472.25746.39764643,712246,0005,104339,0005,800385,000
24303.721.51.252489.33961.64469694,932321,0006,781441,0007,706501,000
24360.5211.524106.02970.17466665,614357,0007,719491,0008,772559,000
26136.2250.52640.05520.70552521,656125,0002,278171,0002,588195,000
26169.424.750.6252649.82426.20753532,097156,0002,883215,0003,276244,000
26202.324.50.752659.49432.75655552,620193,0003,603266,0004,095302,000
262672412678.5450.36864644,029292,0005,540401,0006,296456,000
26330.423.51.252697.19366.96969695,358380,0007,367523,0008,371594,000
26392.5231.526115.45476.26866666,101425,0008,389584,0009,534664,000
28146.9270.52843.19722.31352521,785145,0002,454199,0002,789226,000
28182.726.750.6252853.75128.24853532,260182,0003,107250,0003,531284,000
28218.326.50.752864.20635.31555552,825225,0003,885310,0004,414352,000
28288.42612884.82354.33964644,347341,0005,977468,0006,792532,000
28357.125.51.2528105.04772.29469695,784445,0007,952612,0009,037696,000
28424.5251.528124.87882.36266666,589498,0009,060685,00010,295778,000
30196.128.750.6253057.67830.2953532,423210,0003,332288,0003,786327,000
30234.328.50.753068.91937.87555553,030260,0004,166357,0004,734406,000
30309.72813091.10658.3164644,665393,0006,414541,0007,289615,000
30383.827.51.2530112.90177.61969696,210515,0008,538708,0009,702805,000
30456.6271.530134.30388.45666667,076577,0009,730794,00011,057902,000
3052826.51.7530155.312110.58471718,847710,00012,164976,00013,8231,109,000
30598.126230175.929130.267747410421832000143291131000162831285000

XL Systems–National Oilwell Varco—Viper

Type: Weld-on pin and box Seal: Internal elastomeric and external metal-to-metal

ODWeightID (drift), in.wall thicknessConnection OD, in.Casing wall critical cross-sectional Connection critical cross-sectional Tensile
efficiency, % 
 Compression
efficiency, % 
L-80 Joint strength, kips L-80 Yield torque ft-lbP-110 Joint strength kipsP-110 Yield torque  ft-lbQ-125 Joint  strength kipsQ-125 Yield torque   ft-lb
1672.914.6240.43817.521.41431.038144.999.82,483171,451
1677.714.5640.46817.522.83631.038135.993.62,483171,451
1682.814.50.517.524.34731.038127.587.82,483171,451
16102.714.250.62517.530.18939.675131.498.93,174232,802
16112.614.1240.68817.533.09645.25136.793.73,620234,007
16122.3140.7517.535.93245.25125.986.33,620234,007
18.62585.217.2490.43820.3525.02636.15144.595.12,892223,035
18.62590.817.1890.46820.3526.69636.15135.489.22,892223,035
18.62596.917.1250.520.3528.47136.1512783.62,892223,035
18.625120.316.8750.62520.3535.34345.93813082.33,675271,069
18.625131.916.7490.68820.3538.76953.625138.391.54,290310,389
18.625143.316.6250.7520.3542.11753.625127.384.24,290310,389
2091.618.530.43821.6226.91849.825185.1120.93,986306,595
20104.218.50.521.6230.63149.825162.7106.33,986306,595
20129.418.250.62521.6238.04349.82513185.63,986306,595
20154.3180.7521.6245.35763.925140.991.25,114386,308
20166.617.8760.81221.6248.94863.925130.684.55,114386,308
20203.117.5121.6259.6954.12590.759.34,330452,924
2022716.91.12521.6266.7180.888121.3105.46,471575,810
20250.516.91.2521.6273.63180.888109.995.56,471575,810
20296.616.51.521.6287.17980.88892.880.66,471575,810
2210120.530.43823.829.6755.638187.5145.94,451479,151
22114.920.50.523.833.77255.638164.7128.24,451479,151
22142.820.250.62523.841.9755.638132.6103.24,451479,151
22170.4200.7523.850.06967.225134.3106.65,378576,414
22183.919.8760.81223.854.0567.225124.498.75,378576,414
22224.519.5123.865.97376.925116.696.86,154658,016
2225118.91.12523.873.77886.663117.5115.46,933809,562
22277.318.91.2523.881.48586.663106.4104.56,933809,562
22328.718.51.523.896.60486.66389.788.16,933809,562
24125.622.150.525.836.91468.513185.6168.65,481732,375
24156.222.150.62525.845.89768.513149.3135.65,481732,375
24186.4220.7525.854.78268.513125.1113.65,481732,375
24201.321.8760.81225.859.15282.913140.2116.96,633789,503
24245.921.5125.872.25782.913114.795.76,633789,503
24275.120.91.12525.880.84793.938116.2114.27,515975,484
2430420.91.2525.889.33993.938105.1103.47,515975,484
24360.820.51.525.8106.02993.93888.687.17,515975,484
26136.324.150.527.840.05573.738184.1168.55,899864,301
26169.524.150.62527.849.82473.738148135.55,899864,301
26202.4240.7527.859.49473.738123.9113.55,899864,301
26218.623.8760.81227.864.25490.188140.4116.37,215932,958
26267.323.5127.878.5490.188114.895.27,215932,958
26299.222.91.12527.887.916101.838115.81138,1471,156,863
26330.722.91.2527.897.193101.838104.8102.28,1471,156,863
26392.922.51.527.8115.454101.83888.286.18,1471,156,863
2814726.150.529.843.19779.975185.1164.46,3981,007,147
28182.926.150.62529.853.75179.975148.8132.16,3981,007,147
28218.5260.7529.864.20679.975124.6110.66,3981,007,147
2823625.8760.81229.869.35696.638139.3114.87,7311,088,382
28288.625.5129.884.82396.638113.993.97,7311,088,382
28323.224.91.12529.894.984109.538115.3112.88,7631,353,703
28357.424.91.2529.8105.047109.538104.31028,7631,353,703
28424.924.51.529.8124.878109.53887.785.88,7631,353,703
30157.727.650.53246.338106.988230.9235.88,5591,601,052
30196.327.650.6253257.678106.988185.5189.48,5591,601,052
30234.527.650.753268.919106.988155.2158.58,5591,601,052
3031027.513291.106106.988117.4119.98,5591,601,052
30347.326.781.12532102.053133.125130.4137.910,6501,889,490
30384.226.781.2532112.901133.125117.9124.610,6501,889,490
3045726.51.532134.303133.12599.1104.810,6501,889,490
30528.525.91.7532155.312150.66397110.812,0532,165,271
30598.625.5232175.929150.66385.697.812,0532,165,271
32168.429.650.53449.48113.913230.2231.69,1131,829,649
32209.629.650.6253461.605113.913184.91869,1131,829,649
32250.529.650.753473.631113.913154.7155.79,1131,829,649
32331.429.513497.389113.913117117.79,1131,829,649
32371.328.781.12534109.121142.35130.5134.411,3882,163,167
32410.928.781.2534120.755142.35117.9121.511,3882,163,167
32489.128.51.534143.728142.359910211,3882,163,167
32565.927.91.7534166.308160.796.6109.512,8562,485,833
32641.427.5234188.496160.785.396.712,8562,485,833
34179.131.650.53652.622120.713229.4230.29,6572,073,497
3422331.650.6253665.532120.713184.2184.89,6572,073,497
34266.631.650.753678.343120.713154.1154.69,6572,073,497
34352.831.5136103.673120.713116.4116.89,6572,073,497
34395.430.781.12536116.19150.7129.7133.312,0562,458,775
34437.630.781.2536128.609150.7117.2120.412,0562,458,775
34521.130.51.536153.153150.798.4101.112,0562,458,775
34603.329.91.7536177.304169.63895.7109.113,5712,828,530
34684.229.5236201.062169.63884.496.213,5712,828,530
36282.631.220.7536.8883.056173.3208.7270.813,8642,830,291
36374.231.22136.88109.956173.3157.6204.613,8642,830,291
36419.431.221.12536.88123.258173.3140.6182.513,8642,830,291
36464.331.221.2536.88136.463173.3127164.813,8642,830,291
36553.231.221.536.88162.577173.3106.6138.313,8642,830,291
36640.731.221.7536.88188.299189.5100.692.715,1602,261,941
36726.931.22236.88213.628189.588.781.715,1602,261,941
36811.830.152.2536.88238.565219.391.996.517,5442,884,661
36895.330.152.536.88263.108219.383.387.517,5442,884,661
38298.733.220.7538.8887.768182.75208.2272.714,6203,189,264
38395.533.22138.88116.239182.75157.2205.914,6203,189,264
38443.533.221.12538.88130.327182.75140.2183.714,6203,189,264
38491.133.221.2538.88144.317182.75126.6165.914,6203,189,264
38585.333.221.538.88172.002182.75106.2139.214,6203,189,264
38678.133.221.7538.88199.295201.638101.291.716,1312,548,581
38769.733.22238.88226.195201.63889.180.816,1312,548,581
38859.932.152.2538.88252.702231.11391.596.318,4893,257,936
38948.732.152.538.88278.816231.11382.987.318,4893,257,936
conductor casing pipe grade E & X-42 specifications 30 & 24
conductor casing pipe grade E & X-52 specifications 30 & 24
conductor casing pipe grade E & X-56 specifications 30 & 24

conductor casing pipe grade X-60 & X-65 specifications 30 & 24
conductor casing pipe grade X-80 specifications 30 & 24

Download Conductor Casing Pipe Tables

Casing & Conductor Pipe Tables (Premium Connections)

Vetcogray Connectors and conductor casing pipes specs

Conductor Casing Pipe Connections in Oil And Gas Wells

Conductor Pipe Connectors
Conductor Pipe connection

Conductor casing pipe joints installed on oil and gas land rigs are usually connected by welding beveled prepared ends of the pipes together. This is a time-consuming operation that requires an average of three hours per joint.

On a Jack-up, to reduce the time of the operations and when it is practicable, drivable threaded quick connectors (i.e. the RL-4) and drivable squnch joint connectors such as the Fast Releasing Joint (i.e. the ALT-2), should be used.

A Squnch Joint 

  • A Squnch Joint is a threadless automatic mechanical lock/release connection that makes up without rotation. The extremely strong weight-set connection is well suited for connecting large diameter conductor casing joints, and connecting the casing to the wellhead housing extension.
  • The type ALT-2 heavy-duty squnch joint is used for pipe joins generally up to 36” OD, but larger sizes are available. 
  • It is easily stabbed, drivable, reusable and can be released mechanically. 
  • It is suitable for the severest conditions above the mud line and can be used below the mud line when the conductor is driven into place. The 20” ALT-2 is an ideal high pressure housing extension connector, with an internal pressure rating of up to 5,000psi.
  • The type ST-2 standard duty squnch joint is not a drivable connector. It is used to connect pipe joints up to 30” OD, and is run into a pre-drilled hole and cemented in place. It is recommended for use above the mud line and is reusable and mechanically released.

The Quick Thread Connection

The Quick Thread Connection RL-4 is a very rigid connection for conductor and casing connections and requires just one-quarter turn for full makeup.

The helix angle of the patented, interlocking thread form, in combination with other connector geometries, creates a preload force between the pin and box. The 30” and larger RL-4 conductor casing connectors have a generous shoulder for efficient driving.

the anti-rotation tab

  • Four identical threads 90° apart make-up simultaneously. The thread interface is tapered at 4” per ft of diameter. The connector box has four slots cut on the OD, close to the shoulder of the box and the connector pin has four recessed grooves cut on its OD adjacent to the slots on the box.
  • To activate the anti-rotation tab, a 90° incision is made with the impact tool into the anti-rotation slot. A strip of metal is bent into the recessed groove in the pin which provides a positive mechanical lock.

It does not need power tongs for make-up and is releasable and reusable. It has a high 9° stab angle with dual stab guides. A negative 5° back rake thread interlock reduces belling tendency.

Squnch Joint - Quick Thread Connector
Squnch Joint – Quick Thread Connector conductor pipe

Conductor Casing Pipe Installation Hammers Types For Oil & Gas Wells

Conductor pipe casing hammer installation
Conductor casing pipe installation by hammer

As we mentioned before, a conductor casing pipe (CP) is necessary to provide a riser and flow path for drilling mud from the well to the surface circulating system in Drilling. The outside diameter and the wall thickness of the conductor pipe should be chosen according to previous experiences in the area and the selected casing profile.

Conductor casing Pipe installation can be done either by driving with a pile hammer or by pre-drilling a hole and cementing.

Conductor Casing Pipes Installation Pile Hammers

Diesel pile hammers are used for surface installation & driving operations on conductor casing pipes in oil and gas wells. The driving depth of the conductor casing pipe is a function of the sediments in the ground.

The most commonly used system is the ‘Delmag – D44 or D46’ which has a hammer weight of 18t with a variable delivery fuel pump. The below table shows the specifications of others types of Delmag Hammers. The Manufacturer’s Operating Procedures must be followed when planning driving operations.

Delmag Diesel Hammer Specifications
Delmag Diesel Hammer Specifications for conductor pipe installation in oil and gas wells
Typical Diesel Pile Hammer
Typical Diesel Pile Hammer

The below table shows the normal and maximum blows/ft for different Conductor Casing Pipes and different hammer sizes for installation in oil and gas wells.

Blows/ft for Various CPs and Hammers
Blows/ft for Various CPs and Hammers

Conductor Casing Pipe Installation Hydro-Hammer

Frank’s S-90 Hydrohammer
Frank’s S-90 Hydrohammer

Frank’s Hydro-hammer is an ‘intelligent hammer’ due to its sophisticated electronic control design. This control system is capable of regulating the energy for each impact.

The net energy applied to the conductor pipe while installation, which is measured during every blow, is monitored and can be regulated from the maximum to 5% or less. Since the measure of energy is precisely known, the force applied to the pile can be accurately computed.

One particularly unique advantage of the Hydrohammer is the control system’s ability to shut off the ram automatically if the pile starts to run ahead of the hammer in soft soils, e.g. due to:

  • The hammer is not positioned correctly on the pile.
  • Stroke rate becoming too high.
  • Blow energy is too high.

Other advantages unique to this hydraulic hammer are:

  • It can operate at any angle, even horizontally.
  • It has an optional printer available to produce a report of the piling operation.
  • It can be used onshore or offshore, in air or submerged under water.

Final Refusal Depth For Conductor Casing Pipe Installation For Oil & Gas Wells

The following procedure details the determination of the final refusal depth of the conductor casing pipe installation.

A. When the driving depth of the conductor pipe is not specified in the Drilling Programme, the final depth of the driving is the ‘refusal depth’.

  • The refusal value generally used is 1,000-1,100 blows/metre (300-330blows/ft)
  • Local experience could dictate a different refusal value. The driving depth can be predetermined by conducting soil boring analysis.
  • Examine offset well data for depths and potential problems in order to determine if the CP depth is adequate.

B. The installation driving depth of the conductor casing pipe which is specified in the Drilling Programme is established with the following formula:

Hi = [df x (E+H) – 103 x H]/[1.03 – df + 0.67 x (GOVhi – 1.03)]

where:

Hi = Minimum driving depth (m) from seabed

E = Elevation (m) distance from bell nipple and sea level

H = Water depth (m)

df = Maximum mud weight (kg/l) to be used

GOVhi = integrated density of sediments (kg/dm3/10m)

If the refusal depth does not meet this value, internal washing may be required. CP internal washing might be necessary several times before reaching the planned depth.

C. It should be noted that if there is a high refusal value in very hard formations, the CP shoe could collapse.

Leave a Reply

Your email address will not be published. Required fields are marked *