Standardizing Spatial References Using PPDM AREA Tables

Transcription

1 Standardizing Spatial References Using PPDM AREA Tables Volker Hirsinger, Petrosys Pty. Ltd. Acknowledgments to Mike Silva, Rob Bruinsma, Bob Harms, Craig Aldrich, Alec Kelingos.

2 Introduction Building a best of breed 3.8 demo, just wanted to put in the countries!

3 Standard Place Name Data There are ISO standard place names available -

4 PPDM Legacy Well Location References The district, geographic region, country, province/state and county are all flagged for deprecation in PPDM 3.8, but still widely used:

5 The Problem with Country / State / County Why replace the COUNTY, STATE_PROVINCE, COUNTRY references with the more generic AREA concept? County / state / country has redundant information County / state / country is a North American specific intepretation of more generic geopolitical divisions Some business objects, such as a Joint Venture, may traverse county or state boundaries. Multiple reasons for having area references, eg. Spatial vs. jurisdictional.

6 What are the AREA Tables? Definition of one area of any type State Texas

7 What are the AREA Tables? With a range of labels and descriptions State TX Texas Lone Star State

8 What are the AREA Tables? Managing topological overlapping relationships State TX Texas Lone Star State Harris County

9 What are the AREA Tables? Managing relationships through changes in time or business context (PPDM 3.9) Mexico State TX Texas Lone Star State Harris County

10 What are the AREA Tables? And having associated spatial outlines Mexico State TX Texas Lone Star State Harris County

11 Standardizing Spatial References Using PPDM AREA Tables MAPPING EXISTING DATA INTO AREA

12 Determining the Hierarchy of Country Divisions Commonly encountered data sets don t map spatial references into generic AREA components. Country / State / County structures have to be mapped into a suitable AREA structure. To establish the hierarchy of AREA references, the data needs to be scanned and analyzed.

13 Countries States Counties etc. In the USA, states and counties are all contained in the country USA, and the only way to determine the hierarchy from the database by itself is to analyse the data. The application needs to provide the business rules as to how counties are nested in states.

14 Linking AREA to WELL Using the generic WELL_AREA structure allows the district, country, etc. to be stored along with varying levels of granularity

15 Should WELL Rely on a Single AREA Reference? Using a Single AREA to Define Country-State-County, relying on the AREA hierarchy to fill in the additional detail, represents good data management as it minimises redundancy, however The mechanism for inheriting related objects for incomplete data sets becomes applications and SQL dependent If a data entry screen just asks for a county, it needs to have some context to determine the correct state Applications need to expect missing states or counties in different ways Queries have to drill down through AREA relationships, adding complexity and giving possible performance issues

16 PPDM 3.9 WELL AREA In PPDM 3.9, a single explicit AREA reference is available in the WELL record A properly set up hierarchical AREA table of counties, states and countries can thus provide the state and county data from a single link

17 PPDM 3.9 AREA_HIERARCHY PPDM 3.9 resolves the uncertainty on how counties relate to states etc. in AREA_HIERARCHY

18 Standardizing Spatial References Using PPDM AREA Tables WHAT ARE COUNTRIES?

19 What is a Country? In the international E&P industry we need to have a dynamic view of COUNTRY Fragmentation of countries Sudan, Yugoslavia Merging East Germany Varying levels of federalism United Kingdom Jurisdictional zones Treaty zones Timor Sea

20 When is a Well not in a Country? Timor Sea History of treaty changes in a jointly managed zone 1989 Timor Gap treaty between Indonesia and Australia 2003 Timor Sea treaty between Australia and East Timor 2007 Treaty on Certain Maritime Arrangements in the Timor Sea (CMATS)

21 What is the AREA of a Country? Different boundaries are recognized for different purposes, eg. Australia has many different limits - Exclusive Economic Zone 24nm limit Contiguous Zone 12nm limit Territorial Sea 3nm limit Coastal Waters Map reproduced from Geoscience Australia via

22 How is a Country Identified ISO recommended Two character country codes widely used ISO vs. FIPS-4 Most two character codes are the same but AU is Australia in ISO, Austria in FIPS ID and IN are Indonesia and India in one, India and Indonesia in the other. Desirable to have national language forms of names available May require language option manipulation in database and applications. Côte d Ivoire

23 How Are Areas Identified - Petrosys As unique keys for geopolitical sub-areas such as counties, Petrosys have implemented in their PPDM 3.8 demo: ISO 3166 codes for international subdivisions API codes for USA subdivisions a pragmatic choice reflecting a strong established convention.

24 Standardizing Spatial References Using PPDM AREA Tables OTHER POSSIBLE USES OF AREA

25 PPDM LAND RIGHTS Areas Many possible AREA links: Land right itself Containing political entity county / state etc. Applicable jurisdictional entity Environmental areas CONTRACT links and joint venture areas

26 Land Rights, Contracts and The COMPONENT Quandry In addition to the _AREA link tables PPDM also provides a wide range of _COMPONENT tables that allow cross referencing between objects. Where both sides of a cross-reference have _COMPONENT tables, the data analyst again needs to make a choice which of the two to use: Eg. To tie a contract to an area, you could use AREA_COMPONENT or CONTRACT_COMPONENT

27 Geological Basins A Use for AREA? Some E&P objects, such as geological basins, don t have an explicit home in PPDM as yet. AREA resolves a key problem with geological basins through allowing overlaps via AREA_CONTAIN: Cooper-Eromanga, Cooper, and Eromanga can all be defined individually and found through containing relationships

28 Geological Basins A Use for AREA? Petrosys chose to use STRAT_NAME_SET in place of generic AREA for geological basins: Has logical links to formations and tops Keeps size and performance of AREA table acceptable Keeps stratigraphy module cleaner Cuts out duplication in STRATIGRAPHY_UNIT_COMPONENT

29 Standardizing Spatial References Using PPDM AREA Tables SOME PRACTICAL CONSIDERATIONS

30 Importance of R_AREA_TYPE A decision for the governance council? The choice of AREA_TYPE is important Without defined standards for the reference values for AREA_TYPE, a migration from the explicitly named columns to generic links may result in a degradation of data quality, for example if different data loaders use different AREA_TYPE s for states, provinces and territories.

31 IT View - Avoid Complex AREA References Fine grained AREA_TYPE tables allow accurate representation of the real world, but The more choices available for classifying an area, the more likely the wrong choice will be made Writing and testing query fragments becomes more difficult Database performance suffers through complex query sequences Data quality and completeness audits become more slower and more complex.

32 Business View Give Me The Precise AREA_TYPE Ideally we should separate AREA_TYPE s for PROVINCE_STATE PROVINCE, STATE and TERRITORY Separate country outline area types 24nm limit Contiguous Zone 12nm limit Territorial Sea 3nm limit Coastal Waters

33 Pragmatic Resolution AREA_TYPE Use the more generic STATE_PROVINCE as the AREA_TYPE key to keep applications and user interfaces manageable Use AREA_DESCRIPTION or other metadata to differentiate between states and provinces Can we at least standardise on UPPER CASE natural keys for AREA_TYPE or will matters such as this tempt analysts into using surrogate keys?

34 Summary The AREA tables provide a flexible mechanism for storing spatial references to allow representation of real world spatial relationships which may divert from accepted norms and change over time. The generic nature of the tables means that true standardisation of spatial data management requires acceptance of standard values for the AREA_TYPE reference table, without which the data model does not effectively represent the real world. In addition, the nesting of spatial objects such as counties, states and countries is not pre-defined in the AREA data model, such that business rules need to be implemented at the applications level to define and enforce geopolitical hierarchies. Fast tracking of the implementation of PPDM 3.9 AREA_HIERARCHY, along with standardisation of reference values for common shared spatial objects such as states, is highly recommended.