Ph.D. Theses

Forecasting of oil and gas traps on the north-east board of the Lower Kura depression by high-precision gravity prospecting method

Hasanov Aliaddin Salman

2507.01 - Geophysics, geophysical methods of reconnaissance of the minerals

The main aim of the thesis work was forecasting of oil and gas traps on the north-east board of the Kura depression by high-precision gravity prospecting method, determination of mud volcanoes range zone and directing of exploration works at the result of complex geological and geophysical analysis and synthesis. In order to solve these issues effectively, the results of high-precision gravity prospecting surveys developed on parallel lines were studied at the first stage and Bouguer gravity anomaly values were isotropically and anisotropically transformed at the second stage.

As a result of studies have been carried out, the geological structure of Kura-Talysh, Hajigabul, Navai and surrounding areas was defined, structural complications at southwest periclinal of K.Harami structure were discovered and these structural complications were later confirmed by the CDP method of seismic exploration. For the first time “trap type anomalies” were found in these areas by means of high-precision gravity prospecting method. These anomalies bound by oil-gas bearing were compared to anomalies defined by refracted wave method and conformity between them was enough. It was found out that some of these anomalies related to fracture type sealed anticlinal reservoir (pool) in PF (productive formation) deposit and non anticlinal traps formed by pinching out of I´ horison to I horison of PF.

Bouguer gravity anomaly values were transformed in different radius and their 3D models were given to clarify tectonic properties of geological section sedimentary rock layers, the penetration depth of the mud volcanoes main deposits, geological natures of anomalies typical for region tectonics and etc. According to the results obtained from Bouguer gravity anomaly values transformation it was found out that the depth tectonics of Lower Kura depression north east board deposits were different from sedimentary deposits tectonics. On the other hand, the gradient exists from north-east to south-west area, it should be due to the deep fault. According to obtained information, this deep fault extends from Kalamaddin structure till Kurovdagh and is followed as Neftchala-Kurovdagh deep fault structure continuation.

As a result of the conducted analysis and interpretation we guess that this deep fault is one of the Western-Caspian deep fault transformers. We may guess that oil and gas products penetrate to the upper layers of the earth along the deep fault, and the majority mud volcanoes located along breaking line are oil gas bearing. It would be advisable to use direct search possibility of gravity meter data to discover the oil and gas traps.