Atyrau 2011 - First EAGE Caspian Region Workshop

One of the most sensitive Geotechnical challenges met during the implementation of the Experimental Program (EP) of the Kashagan Oil Project was undoubtedly given by the designing and construction of the artificial islands phases together with their related facilities: the offshore pipelines, trunklines and other submerged infrastructures that had to be layered down within the sea bottom. This work aims to provide a general description of the geotechnical investigations operations that were conducted in the offshore environment by describing the principles that governed the way in which they were performed, from Scope of Works preparation phase to the final data acquisition.

We present the results of the seismic interpretation of high quality, long–offset 2D seismic surveys which have allowed the construction of a palaeogeographical and structural framework of the Caspian Sea sector of the Pricaspian Basin. This sector of the Pricaspian Basin is characterised by a series of carbonate platforms and intervening shale-dominated troughs formed during the Middle Devonian-Early Permian. These structures may be entirely isolated or faulted, with flat roof-tops and the intervening younger strata onlap the slopes around the structures. This interpretation, suggests the following sequential depositional and structural model for the Late Proterozoic-Palaeozoic which then has profound implications for subsequent deposition in the basin: (1) subsidence during an active rifting phase in Riphean times; (2) Devonian rifting ; (3) significant subsidence during the Late Devonian- Middle Carboniferous, with carbonate build-up on the shallow margins and shale deposition in the deep water; (4) increased subsidence due to the collision of the Russian Craton with the Kazakh continent during the Late Carboniferous;(5) salt deposition in the isolated incipient Caspian Sea (6) salt deformation as syn-orogenic sediments were deposited during the Late Permian and onwards

Kashagan is the largest of the fields discovered worldwide in the last 40 years. It is located offshore in North Caspian Sea, Republic of Kazakhstan. Field activities are carried out according to the North Caspian Sharing Agreement by major national and international oil companies. Kashagan is an isolated, pre-salt carbonate platform. It is currently estimated that the field holds about 35 billion barrels of oil-in-place and with associated gas re-injection recoverable reserves could reach 11 billion barrels in 2041. Article provides an overview of the field discovery, regional position and description of Kashagan platform as well as geological reservoir characteristics.

Drill Cuttings Injection (DCI) is worldwide recognised technology and best practicable environmental option for drill wastes utilization. Agip kco is currently implementing first Pilot Project for Drill Cuttings Injection on Kashagan field. Article provides an overview of the project with the emphasis on its subsurface part, in particularlyfeasibility studies, information on drill cuttings injection disposal domain, well, data acquisition and monitoring.

Radial well modeling is a powerful tool of reservoir simulation. Due to excellent spatial resolution of near wellbore zone radial models are used to investigate the flow in the vicinity of the well. Kashagan is a giant offshore oilfield located in the North Caspian Sea, which development has a lot of challenges. Under these circumstances proper planning of the activities is very important. And Radial Well Models were used in Agip KCO in order to plan and support well commissioning operations for Kashagan Experimental Program wells. Simulation studies were performed using Eclipse 300 software. The paper provides brief workflow overview and description of successful Radial Well models applications in Kashagan, as well as models limitations and lessons learned.

From 1994 until present days, North Caspian Sea seismic acquisition methodologies and equipment have changed dramatically. In addition the offshore operations have increased the complexity of the seismic exploration activity. This Paper gives an excursus of the seismic acquisitions carried out by KazakhstanCaspiShelf (KCS) Consortium and by Agip KCO from 1994 to 2007 over the Northern, shallow water sector with particular focus to the North Caspian Sea PSA contracted area of Kashagan. The 1994-1995 2D acquisitions, streamer and ocean bottom cables (OBM) allowed to identify zones of potential oil and gas accumulation within Kazakhstan sector of the Caspian Sea and its coast and to determine priority of oil and gas prospects for exploration and detailed seismic activities. The 2001-2002 3D seismic acquisition over Kashagan allowed the detailed pre and post salt structures mapping. The 2007 3D4C seismic acquisition test over a portion of the Kashagan structure allowed to obtain better interpretation of the pre and post salt layers and the gathering of data for reservoir characterization. The seismic acquisitions in the North Caspian Sea have benefited in the years the methods changes and technologies improvement to allow continuous improvement in the data gathering quality.

The article addresses the need to assess the anisotropy to improve the reliability of seismic imaging and as a consequence, geological models. There are three basic types of anisotropy. It shows examples of analysis and consideration of the anisotropic parameters. It refers to the correctness of the approaches to the analysis of anisotropy.

West Kozhagali – Eskene 2D seismic acquisition is an onshore work, performed by agip kco geosciences team in Kazakhstan. This is the example of successful collaboration with local contractor and clear evidence that RoK companies can contributed to such a complex project as Kashagan field development. The scope of work is to determine the suitability of intra salt-domes basins, Neocomian, Bathonian, Bajocian deep water-bearing horizons for Onshore Plant wastewater injection. The seismic acquisition started in January and shall progress until the end of the 2011. The data is acquired by Kazakhstani contractor SIF Dank LLP through its seismic party located in the area of operations. The subsequent data processing and interpretation steps, which will allow to map and evaluate the possibility of injecting wastewaters into sedimentary reservoir beds, will be carried out by PGD Services in Almaty.

Magnetic hysteresis method can provide rapid, improved, non-destructive characterisation of multiple mineral and fluid components for reservoir characterisation. The advantage of the new hysteresis method is identification of multiple mineral components in the reservoir sample, by acquiring data at a range of low and high applied magnetic fields. Plots of applied magnetic field versus magnetisation, where the slope represents the magnetic susceptibility, provide a universal template upon which any reservoir rock or fluid can be typed and characterised. Pure diamagnetic components, rock matrix minerals such as quartz and calcite, or reservoir fluids such as crude oils and formation waters are characterised by straight lines with negative slope.

КАРТИРОВАНИЕ ПОТЕНЦИАЛЬНО НЕФТЕГАЗОНОСНЫХ ОБЪЕКТОВ В ОБРАЗОВАНИЯХ НЕФТЕКУМСКОЙ СВИТЫ НИЖНЕГО ТРИАСА - ПЕРСПЕКТИВНОЕ НАПРАВЛЕНИЕ НЕФТЕГАЗОПОИСКОВЫХ РАБОТ В РОССИЙСКОЙ ЧАСТИ КАСПИЙСКОГО МОРЯ