1. ‫سالگ‬ ‫درباره‬ ‫چیس‬ ‫همه‬
‫؟‬ ‫چیست‬ ‫سالگ‬ِ‫لَل‬ ‫ٌّگام‬ ‫در‬ ‫پاییي‬ ِ‫ب‬ ُ‫چا‬ ‫درٍى‬ ‫گل‬ ‫دادى‬ ‫ّل‬ ‫بوٌظَر‬ ِ‫ک‬ ‫است‬ ُ‫چا‬ ‫درٍى‬ ‫گل‬ ‫از‬ ‫تر‬ ‫سٌگیي‬ ‫گل‬ ‫یک‬ ‫سالگ‬
‫شَد‬ ‫هی‬ ُ‫استفاد‬ ‫باال‬.‫شَد‬ ‫هی‬ ُ‫استفاد‬ ‫آیٌذ‬ ‫هی‬ ‫بیرٍى‬ ‫خیس‬ ‫بصَرت‬ ‫ّا‬ ِ‫لَل‬ ِ‫ک‬ ‫ٌّگاهی‬ ‫سالگ‬ ‫از‬.
‫بط‬ٍ‫سالگ‬ ‫ٍزى‬ ‫هعوَل‬ ‫ر‬5/1‫تا‬2ppg‫باشذ‬ ‫هی‬ ُ‫چا‬ ‫درٍى‬ ‫گل‬ ‫ٍزى‬ ‫از‬ ‫بیشتر‬.‫هقذار‬ ٍ ‫ٍزى‬ ِ‫البت‬‫دقیق‬‫هی‬ ِ‫هحاسب‬ ‫قابل‬ ‫آى‬
‫باشذ‬.
‫هقذار‬ ‫هعوَال‬‫را‬ ‫گیرد‬ ‫هی‬ ‫حفاری‬ ‫ّای‬ ِ‫لَل‬ ‫در‬ ُ‫شذ‬ ‫پوپ‬ ‫سالگ‬ ِ‫ک‬ ‫ارتفاعی‬ُ‫اًذاز‬ ‫با‬ ‫برابر‬200‫هعادل‬ ِ‫ک‬ ‫فَت‬2‫هی‬ ‫استٌذ‬
‫قاًَى‬ ‫براساس‬ ‫آًرا‬ ‫حجن‬ ‫تَاى‬ ‫هی‬ ِ‫ک‬ ‫گیرًذ‬ ‫هی‬ ‫درًظر‬ ‫باشذ‬U-Tube‫ًوَد‬ ‫گیری‬ ُ‫اًذاز‬ ‫زیر‬ ‫شکل‬ ٍ.
‫دلخواه‬ ‫طول‬ ‫برای‬ ‫نیاز‬ ‫مورد‬ ‫سالگ‬ ‫حجم‬ ‫محاسبه‬:
‫اٍل‬ ِ‫هرحل‬:ُ‫دلخَا‬ ‫طَل‬ ‫برای‬ ‫الزم‬ ‫ّیذرٍاستاتیک‬ ‫فشار‬ ِ‫هحاسب‬
Hydrostatic Pressure in psi = mud weight in ppg x 0.052 x ft of dry pipe
‫دٍم‬ ِ‫هرحل‬:ُ‫چا‬ ‫درٍى‬ ‫گل‬ ٍ ‫سالگ‬ ‫بیي‬ ‫فشار‬ ‫گرادیاى‬ ‫تفاٍت‬ ِ‫هحاسب‬
Pressure gradient difference in psi/ft = (slug weight in ppg – mud weight in ppg) x 0.052

2. ‫سَم‬ ِ‫هرحل‬:‫حفاری‬ ‫ّای‬ ِ‫لَل‬ ‫در‬ ‫سالگ‬ ‫طَل‬ ِ‫هحاسب‬
Slug length in ft = Hydrostatic Pressure in psi ÷ Pressure gradient difference in psi/ft
‫چْارم‬ ِ‫هرحل‬:ِ‫بشک‬ ِ‫ب‬ ‫ًیاز‬ ‫هَرد‬ ‫سالگ‬ ‫حجن‬ ِ‫هحاسب‬
Slug volume in barrel = Slug length in ft x drill pipe capacity in bbl/ft
‫مثال‬:‫؟‬ ‫ًواییذ‬ ِ‫هحاسب‬ ‫را‬ ‫زیر‬ ‫هشخصات‬ ‫برای‬ ‫ًیاز‬ ‫هَرد‬ ‫سالگ‬ ‫حجن‬
Desired length of dry pipe = 200 ft
Drill pipe capacity = 0.016 bbl/ft
Mud weight = 10.0 ppg
Slug weight = 11.5 ppg
Step 1: Hydrostatic pressure required:
Hydrostatic Pressure in psi = 10.0 ppg x 0.052 x 200 ft
Hydrostatic Pressure in psi = 104 psi
Step 2: differences in pressure gradient between slug weight and mud weight:
Pressure gradient difference in psi/ft = (11.5 ppg – 10.5 ppg) x 0.052
Pressure gradient difference in psi/ft = 0.078 psi/ft
Step 3: length of slug in drill pipe:
Slug length in ft = 104psi ÷ 0.078
Slug length in ft = 1,333 ft
Step 4: Slug volume required in barrels:
Slug volume required = 1333 ft x 0.016 bbl/ft
Slug volume required = 21.3 bbl

3. ‫آى‬ ‫از‬ ‫هشخصی‬ ‫حجن‬ ‫اساس‬ ‫بر‬ ‫ًیاز‬ ‫هَرد‬ ‫سالگ‬ ‫ٍزى‬ ِ‫هحاسب‬
‫ًوَد‬ ِ‫هحاسب‬ ‫آى‬ ‫از‬ ‫هشخصی‬ ‫حجن‬ ‫براساس‬ ‫را‬ ‫آى‬ ‫ٍزى‬ ‫تَاى‬ ‫هی‬ ‫باشیذ‬ ‫حجن‬ ‫هحذٍدیت‬ ‫دارای‬ ‫سالگ‬ ‫از‬ ُ‫استفاد‬ ‫در‬ ِ‫چٌاًچ‬.
‫اٍل‬ ِ‫هرحل‬:‫حفاری‬ ‫ّای‬ ِ‫لَل‬ ‫در‬ ‫سالگ‬ ‫طَل‬ ِ‫هحاسب‬
Length of slug in drill pipe in ft = slug volume in bbl ÷ drill pipe capacity in bbl/ft
‫دٍم‬ ِ‫هرحل‬:‫خشک‬ ‫ّای‬ ِ‫لَل‬ ‫برای‬ ‫الزم‬ ‫ّیذرٍاستاتیک‬ ‫فشار‬ ِ‫هحاسب‬
Hydrostatic Pressure in psi = mud weight in ppg x 0.052 x desired length of dry pipe
‫سَم‬ ِ‫هرحل‬:‫هَردًیاز‬ ‫سالگ‬ ‫ٍزى‬ ِ‫هحاسب‬
Slug weight in ppg = (Hydrostatic Prssure (from step 2) ÷ 0.052 ÷ Length of slug in ft
(step1)) + mud weight, ppg, in hole
‫هثال‬:‫؟‬ ‫ًواییذ‬ ِ‫هحاسب‬ ‫زیر‬ ‫هشخصات‬ ‫برای‬ ‫را‬ ‫سالگ‬ ‫ٍزى‬
Desired length of dry pipe = 200 ft
Mud weight in hole = 12.0 ppg
Drill pipe capacity = 0.016 bbl/ft
Volume of slug = 20 bbl
Step 1 Determine Length of slug inside drill pipe in ft:
Slug length = 20 bbl ÷ 0.016
Slug length = 1250 ft
Step 2 Determine hydrostatic pressure required to give desired dry pipe drill pipe
Hydrostatic Pressure in psi = 12.0 x 0.052 x 200

4. Hydrostatic Pressure in psi = 124.8 psi
Step 3 Determine slug weight needed in ppg:
Slug weight in ppg = (124.8 ÷ 0.052 ÷ 1250) + 12.0
Slug weight in ppg = 13.92 ppg
‫حفاری‬ ‫اطالعات‬ ‫هرجع‬ ‫از‬ ِ‫برگرفت‬drlginfo.com
‫هرجع‬:‫کتاب‬Formulas and calculations for Drilling, Production and Workover
‫هترجن‬:‫هَسایی‬ ‫عباس‬