Presentation 01

Petroleum university of technology
Teacher : dr moradi
Provider : masoud bagdeli
In the name of god
Wettability alteration in gas condensate
reservoirs
Autumn 94

‫چیست؟‬ ‫میعانی‬ ‫گاز‬ ‫مخازن‬
‫ایران‬ ‫گازی‬ ‫مخازن‬
‫بررسی‬‫در‬ ‫تولید‬ ‫راهکارهای‬ ‫و‬ ‫مشکالت‬ ‫و‬ ‫مدیریتی‬ ‫روشهای‬‫مخازن‬ ‫این‬
‫روشهای‬‫میعانی‬ ‫گاز‬ ‫مخازن‬ ‫از‬ ‫برداشت‬ ‫ازدیاد‬
‫میعانی‬ ‫گاز‬ ‫مخازن‬ ‫در‬ ‫شئندگی‬ ‫تر‬ ‫تغییر‬ ‫با‬ ‫ارتباط‬ ‫در‬ ‫شده‬ ‫بررسی‬ ‫مقاالت‬ ‫بر‬ ‫مروری‬
‫مطالب‬ ‫فهرست‬

Black oil‫یاه‬‫س‬ ‫نفت‬
Volatile oil‫بک‬‫س‬ ‫نفت‬
gas condensate‫میعاین‬ ‫گاز‬
wet gas‫تر‬ ‫گاز‬
Dry gas‫خشک‬ ‫گاز‬
‫هیدروکربوری‬ ‫مخازن‬ ‫بندی‬ ‫تقسیم‬

‫فازی‬ ‫رفتار‬ ‫نمودار‬

‫ن‬‫مخاز‬‫گاز‬–‫میعانی‬‫عموما‬‫در‬‫عمق‬‫بیشتر‬‫و‬‫در‬‫دما‬‫و‬‫ی‬‫فشار‬‫باالتر‬‫از‬‫ن‬‫مخاز‬‫نفتی‬‫یافت‬‫می‬‫شوند‬.‫د‬‫ر‬
‫سرتاسر‬‫جهان‬‫ن‬‫مخاز‬‫عظیمی‬‫از‬‫این‬‫نوع‬‫در‬‫حال‬‫بهره‬‫ی‬‫بردار‬‫است‬.‫از‬‫جمله‬‫می‬‫توان‬‫به‬‫میدان‬‫س‬‫ر‬‫پا‬‫ج‬‫نوبی‬
‫در‬‫حاشیه‬‫ی‬‫جنوبی‬‫ایران‬‫و‬‫به‬‫ت‬‫ر‬‫صو‬‫مشترک‬‫با‬‫ر‬‫کشو‬‫قطر‬‫ه‬‫ر‬‫اشا‬‫کرد‬.‫ن‬‫مخاز‬‫گاز‬-‫میعانی‬‫ا‬‫ر‬‫عموما‬‫در‬‫قالب‬
‫ن‬‫مخاز‬‫غیر‬‫ل‬‫معمو‬(Unconventional Reservoir)‫دسته‬‫بندی‬‫می‬‫کنند‬.‫دلیل‬‫ی‬‫نامگذار‬‫این‬
‫ن‬‫مخاز‬‫فتار‬‫ر‬‫غیر‬‫منتظره‬(Retrograde Behavior)‫سیاالت‬‫ی‬‫ر‬‫کربو‬‫و‬‫هیدر‬‫موجود‬‫در‬‫آنهاست‬.
‫در‬‫ابتدای‬‫ه‬‫ز‬‫با‬‫ی‬‫مانی‬‫ز‬،‫تولید‬‫این‬‫ن‬‫مخاز‬‫مانند‬‫ن‬‫مخاز‬‫ی‬‫گاز‬‫تک‬‫فاز‬‫فتار‬‫ر‬‫می‬‫کنن‬،‫د‬‫اما‬‫با‬
‫گذشت‬‫مان‬‫ز‬‫و‬‫برداشت‬‫از‬،‫ن‬‫مخز‬‫فشار‬‫کاهش‬‫یافته‬‫و‬‫اجزای‬‫سنگین‬‫تر‬‫از‬‫فاز‬‫ی‬‫گاز‬‫جدا‬
‫شده‬‫و‬‫تجمعی‬‫از‬‫میعانات‬‫گرانبهای‬‫میانی‬(Intermediate Component)‫با‬
C2-C6(‫شامل‬‫ل‬‫مولکو‬‫هایی‬‫که‬‫تعداد‬‫اتم‬‫کربن‬‫آنها‬‫بین‬2‫تا‬6‫است‬)‫ا‬‫ر‬‫تشکیل‬‫می‬
‫دهند‬.
‫میعانی‬ ‫گاز‬ ‫مخازن‬

‫میعانی‬ ‫گاز‬ ‫فازی‬ ‫رفتار‬ ‫نمودار‬
‫برگش‬ ‫گازي‬ ‫مایعات‬ ‫سیستم‬ ‫یك‬ ‫نمونه‬ ‫فازي‬ ‫نمودار‬‫تي‬
‫م‬ ‫تشكیل‬ ‫نمونه‬ ‫منحني‬‫ایع‬

‫بندی‬ ‫دسته‬ ‫به‬‫مربوط‬‫ی‬‫ر‬‫کربو‬‫و‬‫هیدر‬ ‫سیاالت‬‫ترکیب‬ ‫ی‬‫نمونه‬‫ل‬‫جدو‬
‫مختلف‬ ‫ن‬‫مخاز‬

‫بندی‬ ‫تقسیم‬ ‫طبق‬Fevang‫و‬Whitson‫سال‬ ‫در‬1995‫تقسیم‬ ‫جریانی‬ ‫مختلف‬ ‫ناحیه‬ ‫سه‬ ‫به‬ ‫مخزن‬
‫از‬ ‫عبارتند‬ ‫که‬ ‫شود‬ ‫می‬:
‫اول‬ ‫ناحیه‬
‫مایع‬ ‫و‬‫گاز‬ ‫فاز‬ ‫دو‬‫هر‬ ‫وجود‬‫و‬ ‫تولیدی‬ ‫چاه‬ ‫به‬ ‫نزدیک‬
‫است‬‫بحرانی‬ ‫مقدار‬ ‫از‬ ‫بیشتر‬‫شده‬ ‫تشکیل‬‫ی‬‫گاز‬‫میعانات‬‫میزان‬.
‫ند‬‫ر‬‫دا‬‫حرکت‬‫قابلیت‬ ‫دو‬‫هر‬‫میعانی‬‫فاز‬ ‫و‬‫گاز‬‫فاز‬.
‫جریان‬‫ترکیب‬‫ناحیه‬ ‫این‬‫ل‬‫طو‬ ‫در‬(GOR)‫باشد‬‫می‬ ‫ثابت‬.‫که‬‫معناست‬ ‫بدان‬‫این‬‫و‬
‫مخلوط‬ ‫با‬‫ترکیب‬‫لحاظ‬ ‫از‬‫ناحیه‬ ‫این‬‫به‬‫دوم‬ ‫ی‬‫ناحیه‬ ‫از‬‫شده‬ ‫د‬‫ر‬‫وا‬‫گاز‬ ‫فاز‬ ‫تک‬
‫است‬ ‫یکسان‬ ‫چاه‬ ‫از‬‫تولیدی‬.
‫ت‬‫انجام‬ ‫با‬‫و‬‫مایشگاه‬‫ز‬‫آ‬‫در‬ ‫ناحیه‬‫این‬‫ی‬‫گاز‬‫میعانات‬‫اشباع‬‫صد‬‫ر‬‫د‬‫دن‬‫ر‬‫آو‬‫بدست‬‫ست‬
‫ثابت‬ ‫ترکیب‬‫با‬ ‫انبساط‬(CCE,Constant Composition
Expansion)
‫تولیدی‬‫سیال‬‫شبنم‬ ‫ی‬‫نقطه‬‫فشار‬‫طریق‬ ‫از‬‫آن‬‫ی‬‫فشار‬ ‫ز‬‫مر‬ ‫تعیین‬
‫چاه‬ ‫دهی‬‫تحویل‬‫کاهش‬ ‫در‬‫ناحیه‬ ‫مهمترین‬

‫دوم‬ ‫ناحیه‬
‫ناحیه‬ ‫این‬ ‫ابتدای‬ ‫از‬‫میعانی‬‫فاز‬ ‫تشکیل‬‫و‬‫میانه‬ ‫ی‬‫ناحیه‬
‫است‬ ‫بحرانی‬ ‫مقدار‬ ‫از‬ ‫کمتر‬‫شده‬ ‫تشکیل‬‫ی‬‫گاز‬‫میعانات‬‫میزان‬.
‫گاز‬‫فاز‬‫تنها‬‫حرکت‬‫و‬‫است‬ ‫ناچیز‬ ‫خیلی‬ ‫یا‬ ‫صفر‬‫میعانی‬ ‫فاز‬‫تحرک‬
‫ت‬‫انجام‬ ‫با‬‫و‬‫مایشگاه‬‫ز‬‫آ‬‫در‬ ‫ناحیه‬‫این‬‫ی‬‫گاز‬‫میعانات‬‫اشباع‬‫صد‬‫ر‬‫د‬‫دن‬‫ر‬‫آو‬‫بدست‬‫ست‬
‫ثابت‬ ‫حجم‬‫با‬ ‫تخلیه‬(CVD,Constant Volume Depletion)‫و‬
‫آب‬‫فاز‬ ‫تصحیح‬ ‫برای‬‫آن‬ ‫از‬‫استفاده‬
‫س‬‫شبنم‬ ‫ی‬ ‫نقطه‬‫فشار‬ ‫از‬‫استفاده‬‫با‬‫ی‬‫فشار‬ ‫لحاظ‬ ‫از‬‫ناحیه‬‫این‬‫ز‬‫مر‬ ‫تعیین‬‫اولیه‬‫یال‬
‫ن‬‫مخز‬
‫سوم‬ ‫ناحیه‬
‫د‬‫ر‬‫دا‬ ‫وجود‬ ‫چاه‬‫از‬ ‫تر‬‫ر‬‫دو‬
‫ن‬‫مخز‬ ‫داخل‬ ‫سیال‬ ‫شبنم‬‫نقطه‬‫فشار‬ ‫از‬ ‫باالتر‬ ‫ناحیه‬ ‫این‬‫فشار‬
‫گاز‬‫فاز‬ ‫تنها‬ ‫وجود‬(‫خشک‬)‫آن‬‫حرکت‬‫و‬

‫میعانی‬‫گاز‬‫ن‬‫مخاز‬‫در‬‫جریانی‬ ‫مختلف‬‫نواحی‬
‫ن‬‫مخز‬ ‫در‬ ‫جریان‬ ‫مختف‬ ‫نواحی‬

‫ن‬‫مخاز‬ ‫در‬ ‫چاه‬ ‫از‬ ‫فاصله‬ ‫با‬‫مایع‬ ‫و‬ ‫گاز‬‫نسبی‬ ‫های‬ ‫تراوایی‬‫تغییرات‬
‫میعانی‬ ‫گاز‬

‫تولید‬ ‫ی‬ ‫ه‬‫ر‬‫دو‬‫ل‬‫طو‬ ‫در‬ ‫ی‬ ‫گاز‬‫میعانات‬‫و‬‫گاز‬ ‫جریان‬ ‫ی‬ ‫نحوه‬‫گاز‬ ‫ن‬‫مخاز‬‫در‬
‫میعانی‬

‫ب‬ ‫سبب‬ ‫اول‬ ‫ناحیه‬ ‫در‬ ‫گرفته‬‫شکل‬ ‫میعانات‬ ‫جتمع‬‫دو‬ ‫روز‬
‫شود‬ ‫می‬ ‫عمده‬ ‫مشکل‬:
‫شد‬ ‫اجیاد‬ ‫ارزش‬ ‫با‬ ‫میعانات‬ ‫حجم‬ ‫برداشت‬ ‫امکان‬ ‫عدم‬‫ه‬
‫خمزن‬ ‫در‬
‫ش‬ ‫افت‬ ‫نتیجه‬ ‫در‬ ‫و‬ ‫گاز‬‫موثر‬ ‫پذیری‬ ‫نفوذ‬ ‫کاهش‬‫دید‬
‫چاه‬ ‫از‬ ‫تولید‬ ‫قابلیت‬
‫میعانات‬ ‫تجمع‬ ‫مشکالت‬

‫در‬‫خالل‬‫آزمایش‬‫هایی‬‫با‬‫عنوان‬‫ختلیه‬‫با‬‫حجم‬‫ثابت‬‫و‬‫انبساط‬‫با‬‫ت‬‫کیب‬‫ر‬‫ثابت‬،
‫که‬‫در‬‫آزمایشگاه‬‫بر‬‫روی‬‫سیال‬‫خمزن‬‫اجنام‬‫می‬،‫گرید‬‫درصد‬‫میعانات‬‫ح‬‫اصل‬‫از‬
‫افت‬‫تدرجیی‬‫فشار‬‫سیال‬‫تعینی‬‫می‬‫گردد‬.
‫بیشینه‬‫ی‬‫این‬،‫درصد‬‫مالکیست‬‫ای‬‫ر‬‫ب‬‫تقسیم‬‫بندی‬‫خمازن‬‫گاز‬‫میع‬‫انی‬‫به‬‫دو‬‫گروه‬
‫فقری‬‫و‬‫غنی‬.‫جتارب‬‫عملی‬‫نشان‬‫گر‬‫آن‬‫است‬‫که‬‫پدیده‬‫ی‬‫میعان‬‫گاز‬‫حت‬‫ی‬‫در‬
‫خمازن‬‫بسیار‬‫فقری‬‫هم‬‫با‬‫گذشت‬‫زمان‬‫به‬‫افت‬‫شدید‬‫هبره‬‫وری‬‫چاه‬‫م‬‫نجر‬‫می‬‫شود‬.
‫شده‬ ‫تشکیل‬ ‫میعانات‬ ‫مقدار‬ ‫تعیین‬

‫چ‬‫نانچه‬‫مخزني‬‫ي‬‫نفوذپذير‬‫بااليي‬(‫بيش‬‫از‬10‫تا‬15‫ميلي‬‫ي‬ ‫س‬‫ر‬‫دا‬)‫داشته‬،‫باشد‬
‫مي‬‫توان‬‫ن‬‫بدو‬‫اينكه‬‫ان‬‫ر‬‫نگ‬‫تشكيل‬‫ميعانات‬‫در‬‫چاه‬‫بود‬‫با‬‫نرخ‬‫مناسب‬‫ي‬‫از‬‫ن‬‫مخز‬
‫توليد‬‫نمود‬.‫اما‬‫در‬‫د‬‫ر‬‫مو‬‫ني‬‫ز‬‫مخا‬‫كه‬‫ي‬‫نفوذپذير‬‫پاييني‬‫داشته‬‫باشند‬(‫كمتر‬‫از‬
10‫ميلي‬‫ي‬ ‫س‬‫ر‬‫دا‬)‫بايد‬‫نرخ‬‫توليد‬‫ا‬‫ر‬‫ي‬‫ر‬‫طو‬‫ل‬‫كنتر‬‫نمود‬‫كه‬‫مانع‬‫از‬‫سي‬‫ر‬‫دن‬‫فشار‬
‫ن‬‫مخز‬‫به‬‫نقطه‬‫تشكيل‬‫ميعانات‬‫گردد‬.
‫از‬ ‫صیانتی‬ ‫تولید‬ ‫جهت‬ ‫شده‬ ‫پذیرفته‬ ‫راهکارهای‬
‫میعانی‬ ‫گاز‬ ‫مخازن‬
.i‫ش‬‫و‬‫ر‬‫های‬‫ی‬‫جلوگیر‬‫از‬‫تجمع‬‫میعانات‬‫در‬‫ن‬‫مخز‬
.ii‫ش‬‫و‬‫ر‬‫های‬‫بهبود‬‫بهره‬‫ی‬‫ر‬‫و‬‫پس‬‫از‬‫تشکیل‬‫پوسته‬‫ی‬
‫میعانی‬

‫اجیاد‬‫شاکف‬‫های‬‫یکی‬‫ل‬‫یدرو‬‫ه‬
‫حفاری‬‫مورب‬‫و‬‫افقی‬
‫مخزن‬ ‫در‬ ‫میعانات‬ ‫تجمع‬ ‫از‬ ‫جلوگیری‬ ‫های‬ ‫روش‬

‫بر‬‫اساس‬‫نتایج‬،‫تحقیقات‬‫ایجاد‬‫شکاف‬‫لیکی‬‫و‬‫هیدر‬‫می‬‫تواند‬‫تا‬‫سه‬‫ابر‬‫ر‬‫ب‬
‫شاخص‬‫بهره‬‫دهی‬‫از‬‫چاه‬‫های‬‫ن‬‫مخاز‬‫گاز‬‫میعانی‬‫ا‬‫ر‬‫در‬‫هر‬‫دو‬‫محدوده‬‫ی‬‫فشا‬‫ر‬
‫باال‬‫و‬‫پایین‬‫فشار‬‫نقطه‬‫ی‬‫شبنم‬‫ایش‬‫ز‬‫اف‬‫دهد‬.‫شکاف‬،‫لیکی‬‫و‬‫هیدر‬‫م‬‫تناسب‬‫با‬
‫ل‬‫طو‬‫و‬‫شاخص‬‫ن‬‫بدو‬‫بعد‬‫سانایی‬‫ر‬‫خود‬،‫می‬‫تواند‬‫عملکرد‬‫چاه‬‫ا‬‫ر‬‫در‬‫بلند‬
‫مدت‬‫بهبود‬‫بخشد‬.‫در‬‫حقیقت‬‫ایجاد‬‫شکاف‬‫در‬‫ه‬‫ر‬‫دیوا‬‫ی‬‫چاه‬‫که‬‫در‬‫اعماق‬
‫کم‬‫در‬‫استای‬‫ر‬‫عمودی‬‫و‬‫در‬‫اعماق‬‫بیش‬‫از‬۲۰۰۰‫فوت‬‫در‬‫جهت‬‫افقی‬
‫گسترش‬‫می‬‫یابند‬‫باعث‬‫حذف‬‫اثر‬‫پوسته‬‫ای‬‫ی‬ ‫ناش‬‫از‬‫تجمع‬‫میعانات‬‫و‬‫نیر‬
‫ایش‬‫ز‬‫اف‬‫قابلیت‬‫هدایت‬‫جریان‬‫به‬‫ی‬‫سو‬‫چاه‬‫می‬‫گردد‬‫که‬‫این‬‫خود‬‫عاملی‬‫جهت‬
‫به‬‫حداقل‬‫سیدن‬‫ر‬‫آشفتگی‬‫جریان‬‫بوده‬‫و‬‫مانع‬‫از‬‫افت‬‫بهره‬‫ی‬‫ر‬‫و‬‫چاه‬‫می‬‫شود‬.
‫هیدرولیکی‬ ‫های‬ ‫شکاف‬ ‫ایجاد‬

‫یکی‬‫میعا‬ ‫گاز‬‫ن‬‫مخاز‬‫در‬ ‫ایج‬‫ر‬ ‫های‬ ‫آسیب‬‫از‬ ‫ی‬‫جلوگیر‬ ‫ای‬‫ر‬‫ب‬‫شده‬ ‫ائه‬‫ر‬‫ا‬‫های‬‫ر‬‫اهکا‬‫ر‬ ‫از‬ ‫دیگر‬‫نی،حفر‬
‫است‬ ‫افقی‬‫های‬ ‫چاه‬.‫جمله‬ ‫از‬‫فواید‬‫حفر‬‫تولی‬ ‫بیشتر‬ ‫نرخ‬ ‫به‬ ‫توان‬ ‫می‬ ‫ها‬ ‫چاه‬ ‫گونه‬ ‫این‬‫گاز‬ ‫د‬
‫ایجاد‬ ‫از‬ ‫ی‬‫جلوگیر‬ ‫نتیجه‬‫در‬ ‫و‬‫عمودی‬ ‫های‬‫چاه‬‫از‬‫کمتر‬ ‫بسیار‬‫ی‬‫فشار‬‫افت‬‫با‬ ‫ومیعانات‬‫پوسته‬
‫کرد‬‫ه‬‫ر‬‫اشا‬ ‫میعانی‬ ‫ی‬.‫ی‬‫ز‬ ‫بسیار‬ ‫گشودگی‬ ‫و‬ ‫ل‬‫طو‬ ‫با‬‫شکاف‬ ‫یک‬ ‫مانند‬ ‫به‬‫افقی‬‫چاه‬ ‫یک‬‫کرده‬‫عمل‬ ‫اد‬
‫دهد‬ ‫می‬ ‫کاهش‬‫ا‬‫ر‬ ‫تولید‬‫از‬ ‫ی‬ ‫ناش‬‫ر‬‫فشا‬‫افت‬ ‫و‬‫داده‬ ‫ایش‬‫ز‬‫اف‬‫ا‬‫ر‬ ‫ن‬‫مخز‬ ‫با‬‫چاه‬ ‫تماس‬‫سطح‬ ‫و‬.
‫چ‬ ‫از‬ ‫تولید‬‫ایط‬‫ر‬‫ش‬ ‫ی‬ ‫مقایسه‬ ‫با‬ ‫تا‬‫است‬‫انجام‬‫دست‬ ‫در‬ ‫مینه‬‫ز‬ ‫این‬ ‫در‬ ‫ی‬‫بسیار‬ ‫مطالعات‬‫های‬‫اه‬
‫حف‬ ‫آیی‬‫ر‬‫کا‬‫ان‬‫ز‬‫می‬ ،‫آن‬ ‫ن‬‫بدو‬ ‫و‬ ‫لیکی‬‫و‬‫هیدر‬ ‫شکاف‬ ‫با‬‫عمودی‬ ‫های‬‫چاه‬ ‫با‬‫مقایسه‬ ‫در‬ ‫افقی‬‫این‬ ‫ر‬
‫کنند‬ ‫یابی‬‫ز‬‫ار‬‫ا‬‫ر‬ ‫میعانی‬ ‫گاز‬‫ن‬‫مخاز‬ ‫در‬ ‫ها‬ ‫چاه‬ ‫گونه‬.
‫افقی‬ ‫و‬ ‫مورب‬ ‫حفاری‬

.1‫بازگردانی‬‫گاز‬
.2‫عملیات‬‫اسید‬‫ی‬‫کار‬
.3‫یق‬‫ر‬‫تز‬‫حالل‬‫های‬‫شیمیایی‬
.4‫ایش‬‫ز‬‫اف‬‫سرعت‬‫برداشت‬
‫تشکیل‬ ‫از‬ ‫پس‬ ‫وری‬ ‫هبره‬ ‫هببود‬ ‫های‬ ‫روش‬‫پوسته‬‫ی‬‫میع‬‫انی‬

‫عمده‬‫ترین‬‫اه‬‫ر‬‫حلی‬‫که‬‫تا‬‫ن‬‫کنو‬‫ای‬‫ر‬‫ب‬‫فائق‬‫آمدن‬‫بر‬‫پوسته‬‫ی‬‫میعانی‬‫اندیشیده‬‫ش‬،‫ده‬‫باز‬
‫گردانی‬‫گاز‬‫به‬‫ن‬‫و‬‫در‬‫چاه‬‫است‬.‫بدین‬‫ترتیب‬‫که‬‫پس‬‫از‬‫مدتی‬‫تولید‬‫از‬‫چاه‬‫و‬‫افت‬‫فش‬‫ار‬‫جریان‬
‫ته‬‫چاه‬،‫ای‬‫ر‬‫ب‬‫ه‬‫ز‬‫با‬‫ای‬‫مشخص‬‫گاز‬‫ا‬‫ر‬‫باید‬‫به‬‫ن‬‫و‬‫در‬‫چاه‬‫یق‬‫ر‬‫تز‬‫کنند‬.‫بهترین‬‫مقاالت‬‫صنایع‬-
‫ای‬‫ر‬‫ب‬‫گاز‬‫یقی‬‫ر‬‫تز‬،‫گاز‬‫تولید‬‫شده‬‫از‬‫همان‬‫ن‬‫مخز‬‫است‬‫که‬‫میعانات‬‫آن‬‫گرفته‬‫شده‬‫با‬‫شد‬.‫در‬
‫این‬‫آیند‬‫ر‬‫ف‬‫در‬‫وهله‬‫ی‬‫ل‬‫او‬‫فشار‬‫ن‬‫مخز‬‫یابی‬‫ز‬‫با‬‫می‬‫شود‬‫و‬‫سیال‬‫به‬‫حالت‬‫شبه‬‫انی‬‫ر‬‫بح‬‫نزدیک‬
‫می‬‫شود‬.‫در‬‫ضمن‬‫آن‬‫که‬‫میعانات‬‫ایجاد‬‫شده‬‫ه‬‫ر‬‫دوبا‬‫در‬‫گاز‬‫یقی‬‫ر‬‫تز‬‫حل‬‫می‬‫شوند‬‫و‬‫پوس‬‫ته‬‫ی‬
‫ایجاد‬‫شده‬‫تا‬‫حدود‬‫یادی‬‫ز‬‫ناپدید‬‫می‬‫گردد‬.
‫شهای‬‫و‬‫ر‬‫یق‬‫ز‬‫تر‬‫گاز‬‫به‬‫دو‬‫ر‬‫منظو‬‫می‬‫باشد‬:
‫نگهداشتن‬‫کامل‬‫فشار‬‫و‬‫ی‬‫جلوگیر‬‫از‬‫کاهش‬‫آن‬
‫ی‬‫جلوگیر‬‫از‬‫کاهش‬‫شدید‬‫افت‬‫فشار‬
‫گاز‬ ‫ابزگرداین‬

‫ش‬‫و‬‫ر‬‫عمومی‬‫ی‬‫دیگر‬‫که‬‫ای‬‫ر‬‫ب‬‫تحریک‬‫چاه‬‫و‬‫حذف‬‫پوسته‬‫ت‬‫ر‬‫صو‬‫می‬
‫گیرد‬‫عملیات‬‫اسید‬‫ی‬‫کار‬‫است‬‫که‬‫با‬‫ی‬‫شستشو‬‫ه‬‫ر‬‫دیوا‬‫ی‬‫چاه‬‫و‬‫حذف‬
‫پوسته‬‫باعث‬‫ی‬‫ار‬‫ر‬‫برق‬‫جریان‬‫سیال‬‫می‬‫گردد‬.
‫اکری‬ ‫ید‬‫س‬‫ا‬ ‫یات‬‫معل‬

‫این‬‫ش‬‫و‬‫ر‬‫ا‬‫ر‬‫می‬‫توان‬‫آخرین‬‫ی‬‫ژ‬‫تکنولو‬‫ائه‬‫ر‬‫ا‬‫شده‬‫ای‬‫ر‬‫ب‬‫بهبود‬‫ع‬‫ملکرد‬
‫ن‬‫مخاز‬‫گاز‬‫میعانی‬‫دانست‬.‫نتایج‬‫حاصل‬‫از‬‫یک‬‫ی‬ ‫س‬‫ر‬‫بر‬‫دی‬‫ر‬‫مو‬
‫نشانگر‬‫دو‬‫ابر‬‫ر‬‫ب‬‫شدن‬‫شاخص‬‫تولید‬‫در‬۴‫ماهه‬‫ی‬‫ل‬‫او‬‫یق‬‫ر‬‫تز‬‫ل‬‫متانو‬
‫به‬‫ن‬‫و‬‫در‬‫ن‬‫مخز‬‫بوده‬‫که‬‫در‬‫از‬‫ر‬‫د‬‫مدت‬‫این‬‫تأثیر‬‫به‬‫نرخ‬‫بهبود‬‫پ‬‫نجاه‬
‫صدی‬‫ر‬‫د‬‫کاهش‬‫یافته‬‫است‬.
‫شیمیایی‬ ‫های‬ ‫حالل‬ ‫یق‬‫ر‬‫تز‬

‫در‬‫سال‬۱۹۹۴،‫عده‬‫ای‬‫از‬‫محققان‬‫در‬‫دانشگاه‬Heriot Watt،‫اسکاتلند‬‫که‬
‫در‬‫میان‬‫آن‬‫ها‬‫نام‬‫دکتر‬‫انی‬‫ر‬‫ته‬‫و‬‫ر‬‫فسو‬‫و‬‫پر‬،‫دانش‬‫استاد‬‫فقید‬‫دانشگاه‬‫ت‬،‫ان‬‫ر‬‫ه‬‫نیز‬‫به‬
‫چشم‬‫می‬،‫د‬‫ر‬‫خو‬‫ای‬‫ر‬‫ب‬‫اولین‬‫بار‬‫به‬‫نقش‬‫مثبت‬‫ایش‬‫ز‬‫اف‬‫سرعت‬‫برداشت‬‫پس‬‫از‬
‫ایجاد‬‫تجمع‬‫میعانی‬‫در‬‫ناحیه‬‫ی‬‫اف‬‫ر‬‫اط‬،‫چاه‬‫در‬‫ایش‬‫ز‬‫اف‬‫نفوذ‬‫ی‬‫پذیر‬‫نسبی‬‫گ‬‫از‬‫و‬
‫مایع‬‫و‬‫در‬‫نتیجه‬‫ایش‬‫ز‬‫اف‬‫شاخص‬‫بهره‬‫ی‬‫ر‬‫و‬‫ه‬‫ر‬‫اشا‬‫نمودند‬.‫در‬‫حالت‬‫تک‬‫ی‬‫فاز‬،
‫ایش‬‫ز‬‫اف‬‫سرعت‬‫تولید‬‫موجب‬‫ایجاد‬‫جریان‬‫آشفته‬‫و‬‫ایش‬‫ز‬‫اف‬‫نیروهای‬‫لختی‬
(Inertia)‫می‬‫گردد‬‫که‬‫به‬‫نوبه‬‫ی‬‫خود‬‫مانعی‬‫در‬‫ابر‬‫ر‬‫ب‬‫جریان‬‫سیال‬‫ایجاد‬‫می‬
،‫کنند‬‫اما‬‫مایشات‬‫ز‬‫آ‬‫نشان‬‫داده‬‫است‬‫در‬‫ت‬‫ر‬‫صو‬‫وجود‬‫صد‬‫ر‬‫د‬‫باالیی‬‫از‬‫میعانات‬،
‫اثر‬‫یج‬‫و‬‫تز‬‫مثبت‬(Positive Coupling Effect)‫بر‬‫اثر‬‫نیروهای‬‫لختی‬‫غلبه‬
‫کرده‬‫و‬‫جریان‬‫سیال‬‫ی‬‫دوفاز‬‫ا‬‫ر‬‫بهبود‬‫می‬‫بخشند‬.
‫برداشت‬ ‫سرعت‬ ‫افزایش‬

Examinated articles :
Gas – condensate production improvement using wettability alteration : a
gaint gas condensate field case study ( 2014 )
Gas condensate productivity improvement by chemical wettability alteration
( 2009 )
Wettability alteration to intermediate gas-wetting in low – permeability gas
condensate reservoirs ( 2014 )
Gas productivity enhancement by wettability alteration of gas – condensate
reservoirs ( 2007 )
Production enhancement in gas condensate reservoirs by alteration
wettability ton gas wetness :field application ( 2008 )
‫ترشوندگی‬ ‫ات‬‫ر‬‫تغیی‬‫از‬‫استفاده‬‫با‬ ‫میعانی‬‫گاز‬ ‫ن‬‫مخاز‬‫از‬‫ی‬‫ر‬‫و‬ ‫بهره‬ ‫بهبود‬

Gas – condensate production improvement using wettability
alteration : a gaint gas condensate field case study

The reservoir studied in this paper is one of the world's largest
gas condensate fields located in the Middle East. This field has been
produced for about 10 years and the reservoir pressure has
droppedbelow the dew point.
In recent years, wettability alteration, as a new method, has become
more attractive for researchers in industry. Most of the gascondensate
reservoirs rocks are naturally liquid-wetting. Altering the wettability
of the reservoir rock from strongly liquid wetness to preferential gas
wetness or intermediate-wetting can increase the mobility of
condensate and the relative permeability to gas.

Li and Firoozabadi (2000) modeled the wettability alteration in
hydrocarbon systems of gas-condensate-rock. Using experimental methods,
it was shown that the wettability of porous media in gas – liquid rock
systems could be changed from strongly liquid wetness to preferential
gas-wetness . The wettability of the rock was altered by treating it with the
chemical solutions FC759 and FC722 at laboratory conditions.
Tang and Firoozabadi (2002, 2003) performed wettability alteration at high
temperatures up to 90 C and measured the effect of wettability alteration on
liquid mobility. This work has continued by Fahes and Firoozabadi (2005)
for higher temperatures up to 140 C. The results showed that at high
reservoir temperatures, wettability could be permanently altered from
liquid-wetting to intermediate gas-wetting and wettability alteration
significantly increased liquid mobility at reservoir conditions.

Kumar et al. (2006) studied improvement of the gas and condensate
relative permeabilities using chemical treatments under reservoir
conditions. The experimental results showed that when Novec FC
4430 polymeric surfactant was used in the methanol-water mixture
as the solvent, the productivity index was improved by a factor of
2-3 for sandstone cores over the temperature range of 145- 275 F.
Zoghbi et al. (2010) studied an optimum wettability condition to
maximize production enhancement. The simulation results
indicated that when intermediate gas-wetting state was applied in
the near-wellbore region, the gas-condensate well productivity
increased significantly.

The target field is a giant gas condensate field with initial
reservoir pressure and temperature of 365 bars and 376 K,
respectively. The initial condensate to gas ratio (CGR) of
reservoir fluid is around 2*10^-4 Sm^3/Sm^3. According to PVT
experiments results, the dew point pressure is 317 bar. The
composition of the reservoir fluid is given in Table 1.
The studied field is an offshore structure located in the south of
Iran. The reservoir consists in four gas bearing in Kangan and
Dalan formations, so-called layers 1 to 4 from top to bottom.
Kangan and Dalan formations are mainly established of dolomite
with some layers of limestone and anhydrite.

Because of high thickness of productive zones of Kangan and
Dalan formations, drilling of horizontal wells is out of the scope
of the master development plan of the field. The exploration well
of each phase in the field has been drilled vertically.
A single well radial model was constructed based on the valid
reservoir data. The well is vertical and located at the center of the
model with radius (rw) of 0.15 m. The well produces at a constant
surface gas flow rate of about 3 * 10^6 Sm^3/day.
Different block sizes in r, q and Z directions were examined and
suitable grid sizes were selected. The number of grid blocks in r, q
and Z-directions are 38, 1, and 10 respectively. The thickness of
the reservoir is 430 m and the well is perforated along the whole
reservoir thickness.

The value of l found to vary between 0.8 and 1.2 for the
different samples. An average value of 1 has been used for
generating the relative permeabilities.
The relative permeability curves of three different wettability
states are demonstrated in Fig. 4.

The cumulative gas and condensate production were
increased as presented in Table 5. The differences represent
about 8 and 5% increase in cumulative gas production after
altering the reservoir rock wettability to intermediate- and
gas-wetting, respectively.
Also, cumulative condensate production increased over the
reservoirlifetime by 10 and 8%, respectively.

As it can be observed, wettability alteration improves the gas and
condensate relative permeabilities by reducing the condensate
saturation around the well.

Condensate profiles and flow regions of the
different wettability states

1. Both gas and condensate cumulative production were improved greatly after
the wettability of the porous mediawas assumed to be altered from liquid-wetting
to intermediate- or gas-wetting by changing relative permeabilities in the model
for a radius of 5 m around the wellbore.
2.The effect of wettability alteration on gas-condensate production improvement
is more pronounced in the intermediatewetting state.
3. Altering the wettability of the reservoir rock from liquid-wetting to
intermediate- or gas-wetting extends the production plateau and results in
lowering condensate saturation around the well. This increases the well bottomhole
flowing pressure.
4. In the region very close to the well, considering the high capillary number
effects reduced the condensate saturation and increased the relative permeabilities.
5. Wettability alteration could significantly increase well productivity at
relatively low cost because only the near well region needs to be treated.
The main conclusions of this study are:

 The paper proceeds with a survey on gas condensate with emphasis on
chemical wettability alteration. Next , the model description and reservoir
simulation conditions are presented . Then results and discussion are
presented. Then the main conclusions of the study are drawn
 Significant liquid saturations can build up near the wells. Liquid
saturations near the wells can reach 50 to 60 % under pseudo steady –
state flow of gas and condensate . Productivity reductions of 40 – 80 %
have been reported for some fields . It seems that the viscous forces alone
cannot enhance gas well deliverability . Reductions in relative
permeability of greater than 95 % in laboratory cores at low capillary
number have been reported for both low and high permeability rocks .
 During sampling operation in saturated gas condensate reservoirs , some
losses of C7+ components is likely to occur due to liquid drop – out in the
reservoir ( nagarajan 2006 ) . Similarly , part of H2S loss can result from
reaction from with the exposed metal surfaces in the sampling tool .
Gas condensate productivity improvement by
chemical wettability alteration

Methods to recover well productivity

 Wettability alteration in tight gas condensate and gas reservoirs is
deemed to be a key strategy for recovering of lost productivity in gas
condensate wells .
 Chemical wettability alteration of gas condensate wells is recent
development of a broader research field of where wettability alteration
is used for enhanced oil recovery
Chemical wettability alteration
Fc 754 ( cheap cationic surfactant , soluble in water )
Fc 722 ( expensive polymer , insoluble in water )

Saturation profile after 10 years of production
before treatment

 Here we have assumed there is no water in the reservoir and the
surfactant is injected by solving it in alcohol or and organic solvent .
Although this is not a real case. Figure 3 shows that the flow of gas
was improved . The largest effect of treatment between all the cases
is happening for the no – connate water conditions
Case 1 : without connate water

 Seemingly after the treatment the IFT between oil and water as
well as water and rock and oil and rock will decrease and hence
the relative permeability of both phases will shift upward
dramatically and this will mobilize both phases
Case 2 :with connate water of 20 % and 30 %

The cumulative production curves for two diferent
gas composition

The main conclusions of this study are:

A pilot test was designed based on experimental results measured in the
rock sampled from the target gas – condensate reservoir . The gas –
condensate field , located in central china , was a high temperature and
low permeability reservoir with a permeability of less than 0.1 md .about
30000 litters of chemical solution were injected into a well in the gas –
condensate field .
Wettability alteration has been widely studied in oil – water – rock
systems but has not been in gas – liquid (oil or water ) rock systems. This
may be because it is more difficult to alter the wettability in gas – liquid
rock system than in oil-water rock systems.
Production enhancement in gas- condensate reservoirs by altering
wettability to gas wetness : field application

 In tight gas reservoirs, its usually necessary to conduct acid –
fracturing to improve gas production . The problem is the low
liquid return rate after stimulation of acid fracturing which
may cause serious secondary formation damage.
 Recently , panga et al . Studied the application of fluorocarbon
surfactants at different temperatures of 25 C and 126 C to
change the wettability to gas wetness.
 Three types of experiments ( measurement of contact angle ,
spontaneous imbibition and gas flooding ) were conducted to
test the wettability alteration , the stability of the chemicals at
high temperature , desorption and longevity of treatment .
Panga et al. focused on the selection of chemicals according to
temerature stability , long term desorption etc which are
essential in field application .
Production enhancement in gas- condensate reservoirs by altering wettability to
gas wetness : field application

 One of the main concerns was the formation damage caused by
chemical treatment . The formation damage could increase the
capillary pressure . In some course , it was observed that the
increase in capillary pressure due to formation damage
outweighed the reduction in capillary pressure by the
wettability alteration . Thus the wettability alteration was
rendered ineffective.
Production enhancement in gas- condensate reservoirs by altering wettability
to gas wetness : field application

Production enhancement in gas- condensate reservoirs by altering
wettability to gas wetness : field application

Oil and gas production increased with the decrease in producing pressure
in the beginning but then decreased significantly within several days . The
well was almost killed in less than a month
Production enhancement in gas- condensate reservoirs by
altering wettability to gas wetness : field application

Production enhancement in gas- condensate reservoirs by
altering wettability to gas wetness : field application

1. The treatment of wettability alteration to gas wetness using a
fluorocarbon surfactant was applied to a gas condensate well in dongpu
field and it was found that the gas production was increased significantly
However the increase in gas production was not sustained. The main
possible reasons might be due to the exremely low permeability and high
viscosity of liquid condensate .
2. It may be better to choose a production well with a well- known
production history than an appraisal well with a very short or even no
production history
3. It is necessary to investigate the screening criteria ( for example :
the lower limit of permeability ) to apply the treatment of wettability
alteration to gas wetness.
conclusions

Presentation 01

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