3-D Model Based Preliminary Assessment of Shale Gas Resources. Case Study: Central Part of the Lublin Basin Area, Poland

Abstract

Abstract

Shale gas and oil exploration in Poland considerably slowed and to revive it more precise recognition of hot shales position, geometry, maturity, productivity as well as better understanding of the reservoir and geomechanical parameters. To reach this extensive integration of different data types in the form of quantitative 3D geomodels is necessary.

The subject of the presented study is the central part of the Lower Paleozoic Lublin Basin (SE Poland) is a part of the system of sedimentary basins developed along the western slope of the East European Craton (EEC). The basin originated as a late Neoproterozoic rift, followed by the post-rift thermal sag basin (Cambrian–Middle Ordovician). Since the late Ordovician throughout the Silurian oblique collision of the Avalonia with the Baltica led to development of the extensive flexural foredeep basin along the western slope of the EEC, including Lublin region. It is filled with a very thick complex of the Silurian mudstone-claystone-marl sediments. A few tens of meters section in its lower part (Llandovery and Wenlock) is developed as an organic rich mudstone to claystone, being a target for shale gas/oil exploration.

Static modeling methodology used in the study is slightly extended referring to conventional hydrocarbon exploration. In the presented study 2D seismic, well data, laboratory measurements, well logs and results of 1D modelling in BasinMod were used as quantitative input for further Petrel based 3D modeling and resources assessment. The structural – parametric model covers the area 7340 km², it is composed of 4798794 3D cells. Structural framework comprise 9 surfaces (from the top of Silurian to the top of Cambrian), adjusted to stratigraphy of 76 wells. It is divided into Pridoli-Ludlow, Wenlock, Llandovery, Ashgill, Caradoc, Llanvirn, Arenig, Tremadoc complexes. The main scope of the modelling are shales of Wenlock, Llandovery and Caradoc. Modelled parameters involve vitrinite reflectance (Ro), present and original TOC, shale and brittle minerals volumes, RockEval S1+ S2 and HI parameters, bulk density (RHOB), porosity (PHI) and water saturation model. Models are based on laboratory data and well logs interpretation in 15 wells. Using reflectivity model oil, liquid and gas windows were established, and applying modified Schmocker and SPI methods equations preliminary resources assessment for each window was completed. The research realized within the frame of BlueGas (BG1/LUPZAS/13) program.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016