ملخص
هذه الدراسة تتركز على تحسين المعلومات بحل المشاكل الأستاتيكية الناتجة عن الكثبان الرملية في الامتياز (NC210) الذي يقع في حوض مرزق في الجنوب الغربي من ليبيا. وقد ثم اختيار عدد اثنين من الخطوط السيزمية وهما الخط (NC210-05-207) والخط (NC210-05-200) لإجراء هذه الدراسة. تم استخدم طريقتين لحساب التصحيحات الأستاتيكية وتم عرض النتائج. وبلغ طول هذين الخطين )26.5) كيلو متر وتم معالجتهما في شركة شمال أفريقيا للاستكشاف الجيوفيزيائ (NAGECO) باستخدام برنامج (ProMAX software, 2003) وكذلك برنامج (GeoTomo software).تم تطبيق معلومات الإنكسار السيزمي بطريقة (Delay Time Method) وكذلك طريقة حفر الآبار Uphole Method)) في هذه الحسابات. وأخيراً تم عرض أمثلة للمقاطع السيزمية باستخدام هاتين الطريقتين ومناقشة النتائج المتحصل عليها.
Abstract
This study deals with static problems on seismic reflection profiles over sand dunes in concession NC210 in Murzuq Basin southwestern Libya. Two methods of computing field statics have been implemented and the results are presented. Two seismic lines of 26.5 km total length that crossed over sand dunes were processed in North Africa Geophysical Exploration Company (NAGEC) using proMAX software package for seismic data processing and GeoTomo software for inversion static correction softwares for each set of field statics. The refraction field statics are estimated by picking the first break from seismic reflection records using delay time method. The second method of field statics that has been used in this study is the uphole method or conventional method. Examples of brute stack sections of both seismic lines have been presented with two different field statics.range from fair (10%-20%) and lower Nubian (6%-15%). The permeability values range from (2.40 md) to (91.1md), water saturation varies across the reservoir due to the location with respect to the boundaries of the field, averaging 33%. Nubian formation the cement is quartz overgrowth and pore filling cements including anhydrite, chlorite and clays (kaolinite, chlorite and illite/smectite). The oil contact (owc) 3v-59 is defined to be at sub sea depth of 110110 ft. and 97-II NC (OWC) was observed in the reservoir section. The Net Pay is 235 ft at 6% porosity cut off for Q2well, and Q1well the net pay123ft, at 6% porosity, 3v3 the Net pay is 273.5 ft, MOS is 5.64 ft, and residual oil column heigh 7.133 ft, and 3v4 well the net pay equal 324.0 ft, at 6% porosity, Net pay is 273.5 ft, MOS is 3.05 ft, and residual oil column high 2.701ft, and oil saturation 54.66%, Difference in formation water salinity between wells where 3v-59E has salinity of 160,000ppm and OO82 is 215,000 pm. This difference in salinity affects the formation resistivity actor, consequently, the cementation factor because the formation factor depends on many parameters such as porosity, pore size and structure; salinity of connate water and irreducible water saturation.