Kastamonu ve Sinop civarının petrol ve doğal gaz potansiyelinin suda ve toprakta TPH (toplam petrol hidrokarbonları) analizleri kullanılarak belirlenmesi
Determination of the oil and gas potential of surroundings of Kastamonu and Sinop provinces using TPH (total oil hydrocarbons) in water and soil analyses
Yazar: MERT ÖZYAĞCI
Danışman: DR. ÖĞR. ÜYESİ YILDIRAY PALABIYIK
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Petrol ve Doğal Gaz Mühendisliği Ana Bilim Dalı / Petrol ve Doğal Gaz Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2021
Konu: Petrol ve Doğal Gaz Mühendisliği = Petroleum and Natural Gas Engineering

Özet:
Türkiye, kısıtlı petrol ve doğal gaz üretim hacmine sahiptir. Maliyetlerin, yer yer üretimden yüksek olduğu bu yörede, maliyeti düşük yöntemler keşfederek petrol ve doğal gaz bulunması zaruri ihtiyaçtır. Suda ve toprakta TPH (Toplam Petrol Hidrokarbonları) analizi, yeni bir yöntem olarak sondaj kuyusu delmeden, daha düşük maliyetli bir rezerv bulmak amacıyla yer yer Türkiye'de kullanılmaya başlanmıştır. Hidrokarbonlarca zengin bu su kaynakları, kaynak kayaların yüzeyde görülmediği, örtülü veya kaynak kayaların tükenmiş/tüketilmiş olduğu bölgelerde ise petrol ve doğal gaz aramak için önemli bir jeokimyasal araçtır. Özellikle, aktif tektonik ve jeolojik olarak karmaşık havzalarda yapılacak petrol ve doğal gaz aramaları için kaynak kaya hedefli organik kaya ve gaz jeokimyası yerine rezervuar hedefli suda ve toprakta TPH yöntemlerinin birlikte kullanılması daha uygun olabilir. Karadeniz Bölgesi içerisinde yer alan Sinop ve Kastamonu dolayları da yoğun bakır rezervleri ile bilinmektedir. Yoğun bakır rezervlerinin yanı sıra, bu bölgede petrol ve doğal gaz sızıntıları olduğu da bilinmektedir. Boyabat (Sinop) havzası Türkiye'nin Karadeniz bölgesinde yer alan ve petrol potansiyeli bulunan önemli bir bölgedir. Kastamonu bölgesinin alanının temelini tektonik hareketler sonucu bir araya gelen ofiyolitler, Akgöl formasyonu, Devrekani metamorfiti ve İstanbul Paleozoyik istifi oluşturur. Bölgeden alınan su ve toprak numunelerinin laboratuvar analiz sonuçlarına göre, bölgede olgun doğal petrol kaynaklı n-alkan hidrokarbonları tespit edilmiştir. Bu verilerden CPI analizinde, Sinop–Kastamonu yöresi için CPI değerleri genellikle oksitleyici olarak olgun gözlemlenmiştir. Fakat, aynı zamanda bazı değerler olgunlaşmamış olarak nitelendirilen numunelerin de mevcut olduğunu göstermektedir. Bu bölgeden alınan numunelere göre, bazı numunelerin olgunlaşmamış redükte ve oksitleyici, bir kısmının da olgunlaşmış redükte ve oksitleyici olduğu tespit edilmiştir. Pr/Ph-CPI ilişkisinde, su numunelerindeki hidrokarbonların daha oksitleyici hem de redükte olan bölgede bulunduğu ve farklı olgunluk seviyelerine sahip olduğu gözlemlenmiştir. Doğal n-alkan oranına göre Sinop-Kastamonu bölgesinden alınan numuneler için bu değerin neredeyse sıfıra yakın olduğu tespit edilmiş olup, ham petrol göstergesi için uygun koşullar olduğuna işarettir. Surfer programı kullanılarak bölgenin kontur haritaları çıkarılmış ve bölgenin koordinatlarına göre hangi alanlarında hidrokarbon olabileceği belirlenmiştir. Çalışma sonucunda, klasik kaya hedefli organik jeokimyasal yöntemlerine kıyasla, daha az maliyetli ve aynı zamanda daha güvenilir ve tutarlı olan suda ve toprakta TPH analizleri yöntemi kullanılarak petrol ve doğal gaz birikimleri içeren havzaların belirlenebileceği sonucuna ulaşılmıştır.

Abstract:
Turkey has a limited oil and natural gas production volume. In this region where the costs are higher than the local production, finding oil and gas by discovering low-cost methods is an indispensable need. TPH (Total Petroleum Hydrocarbons) in water and soil analyses has started to be used in some places in Turkey in order to find a lower-cost reserve without drilling wells as a new method. These water resources rich in hydrocarbons are an important geochemical tool for oil and natural gas exploration in areas where the source rocks are not visible to the surface or in areas where the source rocks are depleted/depleted. In particular, for oil and natural gas explorations in active tectonically and geologically complex basins, it is more appropriate to use TPH methods in reservoir-targeted water instead of source rock-targeted organic rock and gas geochemistry. Before that, investigations were made using the TPH in water and soil analyses belonging to many regions of Turkey. Among the previous projects, for instance, Beypazarı project aims to investigate the oil and gas potential of the Beypazarı Basin by taking samples from water sources to use the TPH analysis method. Considering the results of TPH analysis, hydrocarbons were detected in all water samples. In addition, it has been reported that TPH values are considerably higher than the hydrocarbon limit values for the recommended surface and groundwater values. Water-rock-hydrocarbon interactions created a hydrocarbon enrichment in the waters in the studied area. It was revealed that the source rocks forming hydrocarbons in the water samples corresponded to the oxic terrestrial environment (Type III kerogen, gas-prone) and mature and over-maturity level. It is considered as a potential gas reservoir in magnetic and gravity maps of the study area, in areas where both gravity and magnetic anomalies are positive, and in fault propagation folds. The purpose of the another project, the Büyük Menderes Graben, was to explore the oil and gas potential of the Büyük Menderes Graben by taking samples from water sources to use the TPH analysis method. It is known that the mature hydrocarbon-rich water samples detected in the study area are important evidence for oil and gas reservoirs. The carbonate source rocks that derive the hydrocarbons in the water samples in the study area were deposited in the marine reduction environment and the organic matter was predominantly composed of Type II (marine) kerogen. The purpose of the other project, in the Seferihisar Uplift, is to investigate the oil and gas potential of the Seferihisar Uplift by taking samples from water sources in order to use the TPH analysis method. While the water samples taken from the Seferihisar Uplift area were analyzed by the TPH method, hydrocarbons were detected in all water samples. Considering the suggested surface and groundwater values, TPH values were determined to be quite high. After the given previous projects, there is no investigation in Sinop-Kastamonu region. Sinop and Kastamonu regions within the Black Sea Region are also known for their dense copper reserves. In addition to the copper reserves, it is known that there are oil and gas seepages in this area. The Boyabat (Sinop) basin is an important region in the Black Sea region of Turkey with oil potential. Ophiolites, Akgöl formation, Devrekani metamorphite, and Istanbul Paleozoic succession, which were come together as a result of tectonic movements, form the basis of the Kastamonu region. Turkey's Central Black Sea Basin is filled with more than 9 km of Upper Triassic and Holocene sedimentary and volcanic rocks. There are oil and gas spills in the basin. There are many large structures associated with expansion and compression tectonics that can be traps for hydrocarbon deposits. Water and soil samples taken from the region have been analyzed in the laboratory and n-alkane hydrocarbons originating from mature natural petroleum were determined in the region. The oil contains large amounts of organic matter and by-products. These products are the main source of organic pollution in these waters due to their mixing with groundwater. There are many organic properties in water samples, such as TPH, which are used to determine hydrocarbon contamination. In TPH, it is a kind of chemical mixture like crude oil. However, these chemicals are all composed of hydrogen and carbon and are generally referred to as hydrocarbons. Petroleum hydrocarbons are grouped according to their behavior in soil and water. These groups consist of different chemicals. The main factors responsible for composition changes in hydrocarbons are source, maturity, migration, and biodegradation. The hydrocarbon content of water samples is significantly higher than the recommended limit values for waters. According to the results of TPH analysis, hydrocarbons were determined in the samples. The source of n-alkanes in water samples is petrogenic hydrocarbons and organically rich rocks. Water-rock-hydrocarbon interactions have created hydrocarbon enrichment in the waters in the studied area and the hydrocarbons in the samples are non-biodegradable. In the CPI analysis of these data, the CPI values for the Sinop – Kastamonu region were generally observed to be mature as oxidizers. However, it has also been found that there are samples whose values are characterized as immature. Pr/Ph values lower than 1 reflect anoxic conditions, while values higher than 1 indicate oxic conditions. According to these values, some samples contain hydrocarbons derived from sediments deposited in an anoxic environment, while the hydrocarbons found in some correspond to an oxic environment. According to the samples taken from this region, some samples were found to be immature reducing and oxidizing while some matured reducing andoxidizing. In the Pr/Ph-CPI relationship, it was observed that the hydrocarbons in the water samples were located in the more oxidizing and reducing region and had different maturity levels. According to the natural n-alkane ratio, this value was close to zero for the samples taken from the Sinop- Kastamonu region. Contour maps of the region were drawn using the Surfer program and it was determined which areas of the region could include hydrocarbon according to the coordinates of the region. It has been determined that the samples contain mixed and non-marine source rock in oxic conditions, but also anoxic marine source rock. There are highly anoxic (Type II, marine kerogen) samples showing high maturity, however mature oxic has been observed in terrestrial (Type III, gas-prone) samples. A significant portion of the samples taken from the study area is very salty carbonate or hydrocarbons associated with evaporitic environments. As a result of the study, it was concluded that basins containing oil and natural gas deposits could be determined using the TPH in water and soil analysis method, which is less costly and at the same time reliable and consistent compared to classical rock targeted organic geochemical methods.