Guidelines applied to the selection/use of tubing grades

tubing grade

guidelines applied to the selection/use of tubing grades

h40

·         an api grade,

·      the yield strength is relatively low and the cost saving over j55 is minimal. this is why h40 is generally not used in tubing sizes,

·         used only for non-critical, shallow wells,

·         do not use for sour service applications,

·         h40 couplings don’t have an api toughness requirement. k55 couplings are used instead.

j55

·        a commonly used grade when it meets the design criteria and has been the “standard” grade for shallow tubing strings (< 9,000 ft) and low-pressure (< 4,000 psi) wells on land,

·         fit for h2s service at all temperatures.

k55

·         fairly common for large diameter surface casing couplings, although line pipe grades x52 and x56 are becoming a popular replacement,

·         fit for h2s service al all temperatures,

c75

·         no longer an official api grade,

·         it was developed as a higher-strength material for sour service but was replaced by l80 tubing.

n80

·         acceptable for sweet oil and gas wells when it meets design conditions.

·         fit for h2s service at temperature greater than 150°f if quenched & tempered (q&t),

·         fit for h2s service at temperature greater than 175°f if normalized (n) & tempered (n&t),

·         normally less expensive than l80 grades.

l80

·         very common tubular grade, and often used for sour service production casing, production liners, and tubing.

·         has a maximum hardness requirement.

·         satisfactory for ssc (sulfide stress cracking) resistance in all conditions but may incur weight-loss corrosion.

·        insist on hot rotary straightening when ordering this product.

·        available in three different chemical requirements: type 1, 9 cr and 13 cr,

·        type 1 l80 is less expensive than 9 cr and 13 cr but more subject to weight-loss corrosion,

·        type 9 cr largely has been replaced by type 13 cr. l80 13 cr tubing has gained popularity because it has good co2 -induced weight-loss corrosion resistance properties; however, it is more costly,

·        type 13 cr may not be suitable in all hydrogen sulphide (sour) service environments. typically, the h2s partial pressure should be less than 1.5 psi for safe use of l80 type 13 cr. for more details, refer to “ nace mr 0175/iso 15156: materials for use in h2s-containing environments in oil and gas production ” issued by the national association of corrosion engineers.

c90

·         api grade,

·         has a maximum hardness requirement.

·         available in two different chemical requirements: type 1 and type 2.

·         only type 1 is recommended for use in sour service.

·         the use of this grade has been generally replaced by t95.

c95

·         not a sour service grade.

·         fit for h2s service at temperature greater than 150°f.

·         usually used for intermediate casing strings that may be exposed to h2sduring a gas kick.

t95

·         a high-strength tubular grade,

·         has a maximum hardness requirement.

·         often used for hpht sour gas production casing strings when l80 and c90 don not have enough strength for the desired well thickness.

·         available in two different chemical requirements: type 1 and type 2.

·         only type 1 is recommended for sour service.

·         sulphide stress cracking (ssc) resistant but not weight-loss resistant.

·         very expensive.

p110

·         the old p105 tubing grade,

·         api has absolutely minimal chemistry requirements for this grade.

·         insist on hot rotary straightening when ordering this product.

·         high-strength tubing typically is used in deep sweet oil and gas wells with high pressures.

·         sensitive to sulphide stress cracking (ssc) failures unless the temperatures are relatively high (> 175°f).

q125

·         api tubing grade, often used for critical service wells.

·         fit for h2s service at temperature greater than 225°f.

·         type 1 chemistry is preferred.