Ham petrol örneklerindeki suyun NMR T2 durulmalarının pik çizgi yarı genişliğinden türetilmesi
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Tarih
2021-06-13
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Yayıncı
Batman Üniversitesi Fen Bilimleri Enstitüsü
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info:eu-repo/semantics/openAccess
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Attribution-ShareAlike 3.0 United States
Özet
NMR Durulma zamanları (T1 ve T2) ile ham petrolün viskozite ve difüzyon katsayı arasındaki
ilişki uzun zamandır ayrıntılı araştıılmaktadır. Petroldeki su ve yağ emülsiyonları, fraktür
karakterizasyonu, geçirgenlik tahmini, granüller paketlerde ve kayalardaki su ve petrolün dinamiği ve
ham petrolün NMR relaksiyon dispersiyon özellikleri de NMR tekniği incelenmektedir. Petrol
çalışmalarının büyük ekseriyeti düşük alan NMR ile yapılmıştır. Ancak düşük alan NMR cihazları pikleri
birbirinden ayıramamaktadır. Bunun sebebi ise, NMR cihazlarının, üst üste binen piklerden oluşan
kompozit bir pik vermesidir. Bu pikleri değerlendirebilmek için geleneksel olarak kullanılan Fourier
Transform tekniği yerine rölaksasyon inversyonu denilen bir matematik teknik kullanılmaktadır. Ancak
durulma zamanları ölçümlerinde kullanılan teknikler zaman tüketicidir. Ayrıca Radyasyon damping
denilen olar da, yüksek alanlarda, durulma zamanı ölçümlerine imkan vermeyebilir. Diğer taraftan NMR
piklerinin çizgi yarı genişliğinden 1/T2 durulma oranın türetimesi, son yıllarda sıkça yapılan çalışmalara
konu olmuştur. Bu tezin amacı da petrol sıvısının NMR spektrumdan elde edilen su piklerinin çizgi yarı
genişliğinden 1/T2 zamanını türetmektir. Bu amaç için 23 ham petrol örneği Batman yöresinde bulunan
değişik kuyulardan alındı. Her bir kuyudan alınan 0.06 mL petrole ve 0.94 mL dötorokloroform(CDCl3)
eklenerek karışımlar hazırlandı. Ayrıca 0.90 mL D2O’ ya, 0.02 mL lik adımlarla, artan sıvı miktarları
eklenerek, 5 farklı konsantrasyon seti hazırlandı. Diğer bir kuyudan alınan ve H2O piki vermeyen petrol
sıvısına %20 oranında su ilave edildi. Bu tüpe aktarılan bu karışım bir ay boyunca her gün çalkalandı.
0.02 mL lik adımlarla artan 5 konsantrasyon seti bu örnek içinde hazırlandı. Karışımlar hazırlandıktan
hemen sonra 5 mm çapındaki NMR tüplerine aktarıldı ve NMR ölçümleri de hemen alındı. Ölçümler 400
MHz NMR spektrometresi ile tek puls adımı kullanılarak gerçekleştirildi. Pik yarı genişlikleri, su
piklerinin yüksekliğinin yarısından yatay eksene paralel hareketle kursor yardımı ile bulundu. 400 MHz
NMR ile elde ettiğimiz spektrum, biri 1.56 pp civarında ve diğeri 4.71 civarında iki pik vermektedir. Bu
piklarin spin-spin durulma oranları (1/T2), 1/T2 ile çizgi yarı genişliği arasındaki ilişkiyi belirleyen
bağıntıdan hesaplandı. Deneysel veriler literatürle tutarlı olup, 1/T2 değerlerinin kuramsal bağıntıdan
elde edilebileceğini göstermektedir. 4.71 ppm’deki su piki tüm orneklerin spektrumunda çıkmamaktadır
ve su ilave ettiğimiz örneğin spektrumunda da yoktu. Ancak su ilave ettiğimiz örnekte ortaya çıktı. Bu
bulgu bir kuyunun petrolünde su bulunup bulunmayacağının tespiti için yararlıdır. Çizgi yarı genişliğinin
petrol miktarına bağlılığı lineer bılundu. Bu da su moleküllerinin bağlı ve serbest faz arasında hızlı
kimyasal değiş tokuş yapması ile tutarlıdır.
The relation of NMR spin-lattice and spin-spin relaxation times (T1 and T2) to the viscosity and diffusion coefficient of crude oil has been studied in detail for a long time. In oil and water emulsions in oil, fracture characterization, permeability estimation, dynamics of water and oil in granular packages and rocks, and NMR relaxation dispersion properties of crude oil are also examined by the NMR technique. The vast majority of oil studies have been done by low field NMR. However, low field NMR devices cannot distinguish the peaks from each other. This is because NMR devices give a composite peak consisting of overlapping peaks. To evaluate these peaks, a mathematical technique called relaxion inversion is used instead of the traditionally used Fourier Transform technique. However, the techniques used in the relaxation time measurements are time consuming. In addition, so-called Radiation Dumping may not allow for settling time measurements in high areas. On the other hand, the derivation of the 1/T2 relaxation rate from the line half-width of NMR peaks has been the subject of frequent studies in recent years. The purpose of this thesis is to derive the time 1/T2 from the half-line widths of the water peaks obtained from the NMR spectrum of the petroleum liquid. For this purpose, 23 crude oil samples were taken from different wells in Batman region. Mixtures were prepared by adding 0.06 mL of oil and 0.94 mL of deuterochloroform (CDCl3) from each well. In addition, 5 different concentration sets were prepared by adding increasing amounts of fluid in 0.02 mL steps to 0.90 mL D2O. 20% water was added to the petroleum fluid taken from another well, which did not peak H2O. After preparation, the mixtures were immediately transferred to 5 mm diameter NMR tubes and NMR measurements were taken immediately. Measurements were carried out with a 400 MHz NMR spectrometer using a single pulse sequence. Peak half-line widths were found with the aid of a cursor from the half- height of the water peaks. The spectrum obtained with 400 MHz NMR gives two peaks, one around 1.56 pp and the other around 4.71 ppm. The spin-spin relaxation rates (1/T2) of these peaks were calculated from the relation between the 1/T2 and half-height line width. Experimental data are consistent with the literature and show that 1/T2 values can be obtained from the theoretical relation. The water peak at 4.71 ppm appear only the spectrum of some samples, and it was not in the spectrum of the sample to which we added water. This finding is useful for determining whether there is water in the oil of a well. Dependence of the line width on oil content was found to be linear. This is consistent with the rapid chemical exchange of water molecules between the bound and free phase.
The relation of NMR spin-lattice and spin-spin relaxation times (T1 and T2) to the viscosity and diffusion coefficient of crude oil has been studied in detail for a long time. In oil and water emulsions in oil, fracture characterization, permeability estimation, dynamics of water and oil in granular packages and rocks, and NMR relaxation dispersion properties of crude oil are also examined by the NMR technique. The vast majority of oil studies have been done by low field NMR. However, low field NMR devices cannot distinguish the peaks from each other. This is because NMR devices give a composite peak consisting of overlapping peaks. To evaluate these peaks, a mathematical technique called relaxion inversion is used instead of the traditionally used Fourier Transform technique. However, the techniques used in the relaxation time measurements are time consuming. In addition, so-called Radiation Dumping may not allow for settling time measurements in high areas. On the other hand, the derivation of the 1/T2 relaxation rate from the line half-width of NMR peaks has been the subject of frequent studies in recent years. The purpose of this thesis is to derive the time 1/T2 from the half-line widths of the water peaks obtained from the NMR spectrum of the petroleum liquid. For this purpose, 23 crude oil samples were taken from different wells in Batman region. Mixtures were prepared by adding 0.06 mL of oil and 0.94 mL of deuterochloroform (CDCl3) from each well. In addition, 5 different concentration sets were prepared by adding increasing amounts of fluid in 0.02 mL steps to 0.90 mL D2O. 20% water was added to the petroleum fluid taken from another well, which did not peak H2O. After preparation, the mixtures were immediately transferred to 5 mm diameter NMR tubes and NMR measurements were taken immediately. Measurements were carried out with a 400 MHz NMR spectrometer using a single pulse sequence. Peak half-line widths were found with the aid of a cursor from the half- height of the water peaks. The spectrum obtained with 400 MHz NMR gives two peaks, one around 1.56 pp and the other around 4.71 ppm. The spin-spin relaxation rates (1/T2) of these peaks were calculated from the relation between the 1/T2 and half-height line width. Experimental data are consistent with the literature and show that 1/T2 values can be obtained from the theoretical relation. The water peak at 4.71 ppm appear only the spectrum of some samples, and it was not in the spectrum of the sample to which we added water. This finding is useful for determining whether there is water in the oil of a well. Dependence of the line width on oil content was found to be linear. This is consistent with the rapid chemical exchange of water molecules between the bound and free phase.
Açıklama
Anahtar Kelimeler
400 MHz NMR, Crude Oil, Water Immiscible With Crude Oil, Water Associaded With Crude Oil, T2 Relaxations, Ham Petrol, Ham Petrol İle Karışmayan Su, Ham Petrol İle İlintili Su, T2 Durulmaları
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Künye
Taşer, Ö. (2021). Ham petrol örneklerindeki suyun NMR T2 durulmalarının pik çizgi yarı genişliğinden türetilmesi. (Yayınlanmamış Yüksek Lisans Tezi). Batman Üniversitesi Fen Bilimleri Enstitüsü, Batman.
