Zechstein Prospect Evaluation North Sea
Please Select:
Summary    List of Contents    Basemap    Complementary Products


Contents

NORTH SEA ZECHSTEIN PLAY

GEOLOGY
Over 100 graphic and text slides are included covering:

• Basin Stratigraphy - a series of sketches to illustrate the variations in the Zechstein basin fill across the North Sea region and also from where analogues can be drawn.

• Diagensis - 6 slides present Clark's (1986) 4 phase diagentic model

• Z1, Z2 and Z3 Carbonates - 6 slides introduce the features and properties of these carbonates together with regional observations within the area of interest. The reservoir potential is also discussed and cross plots on the core data from the onshore Malton Field (Z2 and Z3 carbonate) are included.

• Observation from Polish Fields - the regional uniformity within the Zechstein basin allows the use of these field analogues to benchmark this study. 18 slides describe the stratigraphy together with analysis of gas flow rates, pressure, poroperm and saturation. A summary slide and map are included.

• Polish Exploration Techniques - 4 slides summarise the type and location of the main reservoirs and the exploration tools used.

• Known Discoveries - 2 slides show the area/depth plots for both a Z2 carbonate discovery and a Z3 carbonate discovery with 2 slides of commentary.

• Reservoir Data - 30 slides cover the following aspects for the Z2 and Z3 with summary data for the Rotliegend
  • well logs
  • test data
  • facies maps
  • palaeogeography
  • core data and interpretation
  • isochore maps
• Source Rocks - regional burial model.

• Prospects - over 50 Z2, Z3 Rotliegend prospects are identified by area and summarised on 14 slides.

• Reserves - 8 slides cover the reserves by prospect and prospectivity with the parameters used.

• Play Maps - 4 slides cover the regional play fairways map and commentary

• Summary - the 'Top 20 Prospects' are highlighted


GEOPHYSICS
Over 140 graphic and text slides are included. These are divided into 5 sub sections:

• Introduction and Regional Setting - 12 slides cover the location of the study area and structural features.

• Database
  • Seismic - the seismic surveys in the area are described and details from over 6,700 km seismic data which were interpreted are provided.
  • Wells - the 25 offshore wells and 3 onshore wells studied in depth are listed, together with 8 further wells that were only briefly reviewed. The 19 wells with seismic ties are identified.
  • Seismic ties - for each well the key events picked for seismic interpretation purposes are listed. Information is given for depth (mss), TWTs, average velocities and interval velocities for each seismic package. Details of any necessary 'datum shifts' are included. A Top Plattendolomite time/depth plot is calculated.
• Interpretation and Mapping - 4 slides provide details of the interpretation methodology used and the events picked are described on a 'reflector summary slide'.

• Results and Seismic Examples - this section contains:
  • Prospect locations - 2 slides
  • Structural elements map and description - 2 slides
  • Carboniferous subcrop maps - 4 slides
  • Example discoveries and seismic well ties - 12 slides
  • Seismic examples of structural styles - 24 slides
  • Seismic examples of specific prospects - 41 slides
  • Examples of stratigraphic traps - 8 slides
• Conclusion - this slide summarises the geophysical results and implications for exploration in the area.

• Regional TWT Structure Map (Separate enclosure) at 1:125,000 scale on the Top Z3 reservoir. This covers about 56 North Sea blocks; about 95% of the area is in the 21st Licensing Round. 90 undrilled structures are identified, over 50 of which we currently classify as prospects.

DEVELOPMENT PLAN, ENGINEERING AND ECONOMICS
85 slides consider conceptual development plans, engineering and economics in sufficient detail to indicate the commercial viability of the prospects described in the geology and geophysics sections.

• Engineering Issues - 20 slides address these issues including:

- Environment - the sensitivity of the coastline, seabed and marine life is addressed.

- HSE - the design, construction and operation under HSE guidelines is provided. The quality of the gas and in particular the H2S content is discussed. Detailed gas analysis is provided with details of the required processing and commercial implications.

• Exploration Risk and Approach - these are briefly introduced in 4 slides.

• Development Plan - 3 distinct plays are studied in detail and full development plans for each cover the following (50+ slides):
  • reserves, well development programme and productivity
  • pipeline details and routing
  • landfall options
  • onshore processing facilities
  • capex and opex
  • commercial assumptions and economics
• Conclusions - these are covered in 4 slides.

• Engineering Appendix - a separate engineering annex provides more background details on design, cost estimates and economic valuations.