Rosgeo has finished the Bazhenovskaya stratigraphic well drilling

30.10.2018
Courtesy of rosgeo.com

AO PTs Nedra (the city of Yaroslavl, the company is part of Rosgeo state parent company) has finished the drilling of Bazhenovskaya stratigraphic well No. 1, having achieved a hole target – 3,200 meters (actually, the depth made up 3,202.8 m).

The well is situated in the West Siberian oil-and-gas province (the Tyumen Region, Yugra, Khanty-Mansiisk Autonomous District).

The project goal is to study the geological structure and assess the oil-and-gas content of the Mesozoic sedimentary cover (including the Bazhenovsko-Abalaksky deposits) and the contact area with the pre-Jurassic complex in the South-Western part of Lyaminsky petroleum district, the development of studying methods of potentially productive horizons within the Bazhenovsky field testing site.

Based on the results obtained from operational processing and interpretation of geographic information system (GIS) and geological and engineering survey data, and also correlations with the logs of neighboring drilled wells, the following was established: the preliminary depth of the Bazhenovsky deposits’ deroofing – 2,792 m; the residuum of the pre-Jurassic sedimentary complex (which is the foundation for Western Siberia) – 3,029.6 m, and the foundation – 3,034 m.

The obtained results will be clarified in the course of core studies and overall tie with the GIS data.

Five objects were tested in the open hole formation tests. There were no complications in the course of the works. It was found out that the intervals of the Frolovsky Suite of Bazhenovsky-Abalaksky complex were practically impermeable, and the Tyumen complex was law permeable. It was concluded that there were beds in the section of Bazhenskaya Suite, which could be classified as "a possible collector."

Core samples collection made up 643,8 m; core recovery –  574,98 meters (89,3 %). The core samples were collected in fiberglass core tubes from the deposits of the Bazhenovsky-Abalaksky complex in the interval from 2,800 to 2,839 meters. It was done to ensure the preservation of the primary rock qualities. The samples were taken from each crosscut end for operational research. According to the primary description of the samples taken on the drilling site, the deposits were bituminous argillites, frequently carbonated; there was cracking and micro cracking on the rock stratification. A part of the samples had a greasy feel; there was smell of hydrocarbons upon abrasion. The capacity of the Bazhenovsky-Abalaksky complex with regard to Bazhenovskya-1 well made up 54 m.

All isolated core was delivered in time to specialized laboratories of the Autonomous Institution of Yugra, the Khanty-Mansiisk Autonomous District, "The Scientific and Analytical Center for Rational Subsoil Use named after V. I. Shpilman" to the city of Khanty-Mansiisk, where samples were taken for mass, detailed and special research.

The works were performed under the state contract concluded last year between the parent company and the Department for Subsoil Use in the Ural Federal District. The term of the state contract is valid until the end of 2019. It is planned for the next year to study the lithological composition of the rocks, their reservoir characteristics, elaboration of the GIS complex technology and core selection. Vertical seismic profiling, extended GIS complex including full wave acoustic, lithodensity, nuclear-magnetic, gas, carbon-oxygen and spectrometric logging will be conducted in the well.

Comprehensive laboratory studies are conducted with the selected core material, sludge and reservoir fluids, including 80 different methods.

By the end of 2019, the all stratigraphic information will be given to the customer together with the final report on the subsoil geological studies.

Source: rosgeo.com

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