Volume 3, Nº 2 (2021)

The second part of the article on deep-water deposits in the Norflet formation in the Gulf of Mexico discusses the history of discoveries as a result of the implementation of the largest geological exploration project as well as the project for the development of discovered fields implemented by Shell.

The history of the Appomattox field discovery is discussed in more detail. This discovery played a key role in the entire history of this project, becoming the trigger for the transition to an unprecedented pace of exploration for ultra–deep horizons in ultra-deep water (in total – over 10 km).

Prospects for further E&A activity for Norflet formation in the Gulf of Mexico considered in the final part.

The article describes one of the methods of enhancing oil recovery, the experience of its application, including global, and the design of the development (using 3D reservoir simulation) with the arrangement of the pilot area, taking into account the peculiarities of the method.

This paper presents the interpretation of the results of biomarker analysis and oil fingerprinting of all producing wells (36 samples) of Nuraly field for genetic typing and fluid communication assessment within the field, followed by predicting the hydrocarbon migration pathways. According to the biomarker study, it was revealed that the oils of central and western Nuraly have genetically different origins, and the petroleum accumulation in the southern part of West Nuraly was formed by the continuous secondary migration of HC from the northeastern and northwestern directions. Oils from central Nuraly field have higher thermal maturity and lower density than those of western Nuraly do. The thermal maturity of samples from Central Nuraly decreases from the northeastern part of Nuraly towards the southwestern part, which may also attest to hydrocarbon migration pathways. The presence of gas caps in the northeastern part of Central Nuraly may be due to their high thermal maturity.

The paper presents a technology for controlled deep penetrating perforation using the Perfobur technical system to intensify inflow by drilling radial channels 69 mm in diameter, up to 25 metres in length. This technology was first applied to a carbonate reservoir in the Bashkirian tier, characterised by high heterogeneity and close proximity of bedrock water. An adjacent well, close to the acid fracture well, with identical reservoir properties, was selected. Well "A" was acid fractured and well "B" was drilled using Perfobur technology with two directional channels, each 14 metres in length. In well "B", after drilling the channels, hydrochloric acid solution was injected through a special hydromonitor nozzle at two points. A total of 48 m3 of acid was injected into the "B" well. Comparing the results of well "B" with the well where the hydrofracturing was performed allow speaking about high efficiency of the controlled radial drilling technology. The ability to predict the channel trajectory, knowledge of its actual trajectory in combination with acid treatment of the reservoir using hydromonitor nozzle at a considerable distance from the reservoir allows achieving a significant increase in oil flow rate with lower water cut of the produced oil.