The EDM database has a hierarchical data structure to support the different levels of data that are required by different drilling suite applications. EDM uses the following hierarchical levels:
EDM™ Hierarchical Data Structure
Hierarchical Level
Description
Database Database is the highest level in the Well Explorer hierarchy. You can only work in one database at a time. For more information, see “Working at the Database Level” on page 3-7.
Company Company is the second-highest data level in the hierarchy. You can define several companies within the database you are using.
Each company must have a unique name. If you work for an operator, you most likely have only one company. If you work for a service company, you may have several companies. For more information, see “Working at the Company Level” on page 3-14.
Project Project is the data level directly beneath company. Each project within a company must have a unique name. A project can be thought of as a field or as a group of sites. A project has one system datum (mean sea level, lowest astronomical tide, and so on) that is used to define 0 TVD for the project. Within the project, wellbores can be referenced to the project level system datum or to additional datums specified at the well level. For more information, see “Using Datums in EDM™” on page 2-21 or “Working at the Project Level” on page 3-35.
Company
Chapter 2: The Engineer’s Data Model (EDM™) Database
Site Site is the data level directly beneath the Project level. Each site within a project must have a unique name. A site is a collection of one or more wells that are all referenced from a local coordinated system centered on the site location. A site can be a single land well, an offshore subsea well, a group of wells drilled from an onshore pad, or a group of wells drilled from an offshore platform. For more information, see “Working at the Site Level”
on page 3-45.
Well Well is the data level directly beneath the Site level. Each well within a site must have a unique name. A well is simply a surface location. A well can have more than one wellbore associated with it. For example, the original wellbore may have one or more sidetracks tied on to it at different kick-off depths. For more information, see “Working at the Well Level” on page 3-56.
Wellbore Wellbore is the data level directly beneath the Well level. Each wellbore within a well must have a unique name. A wellbore is a compilation of one or more sections originating at the surface and continuing to a depth. A wellbore can be the original well drilled from the surface or a sidetrack drilled from a parent wellbore. If a well has an original hole and two sidetracks, the well has three wellbores. For more information, see “Working at the Wellbore Level” on page 3-64.
Design Design is the data level directly beneath the Wellbore level.
Each design within a wellbore must have a unique name. A design can be thought of as a design phase. Associated with each design are a pore pressure group, a fracture pressure group, a temperature gradient, and a survey. A design may have several cases associated with it, but each case will use the same pore pressure group, fracture pressure group, temperature gradient, and survey. A design can be categorized as prototype, planned, or actual. You may have several different versions of prototype designs. For example, assume the geologist wants to analyze two different formation fracture gradients. This could easily be accomplished by having two prototype designs that are identical except for the fracture gradient group. The StressCheck and COMPASS applications routinely use designs. For more information, see “Working at the Design Level” on page 3-66.
EDM™ Hierarchical Data Structure
Hierarchical Level
Description
COMPASS™ Software Release 5000.1.7 Training Manual 2-5 Chapter 2: The Engineer’s Data Model (EDM™) Database
Associated Components
This section discusses several additional data components that are associated with designs or cases.
Associated with Designs
Wellpaths
A wellpath is a series of survey tool readings that have been observed in the same wellbore and increase with measured depth. All cases within the same design use the same wellpath.
Pore Pressure Groups
A Pore Pressure group is a set of pore pressures that define the pore pressure regime over a depth range from surface to some vertical depth.
All cases within the same design use the same pore pressure.
Fracture Gradient Groups
A Fracture Gradient group is a set of fracture pressures that define the fracture gradient regime over a depth range from surface to some vertical depth. All cases within the same design use the same fracture gradient.
Geothermal Gradient Groups
A Geothermal Gradient group is a set of undisturbed earth temperatures that define the temperatures over a depth range from the surface to some vertical depth. All cases within the same design use the same
geothermal gradient.
Associated with Cases
Hole Section Groups
A Hole Section group defines the wellbore as the workstring would see it. For example, a hole section may contain a riser, a casing section, and an open hole section. A hole section can also have a tubing section or a drill pipe section depending on the situation. Multiple cases may use the same hole section.
Chapter 2: The Engineer’s Data Model (EDM™) Database
Assemblies
An Assembly defines the workstring. There are several types of workstrings, including coiled tubing, casing, drillstrings, liners, and tubing strings. Multiple cases may use the same assembly.
Fluids
A Fluid defines a drilling, cementing, or spacer fluid. A Fluid is linked to a case and a case can have more than one fluid linked to it. One fluid can be linked to multiple cases.
Copying and Pasting Associated Items
All of these associated items, with the exception of fluids, are
automatically created and associated (linked) by Well Explorer to the design or case.
All of these items are visible in Well Explorer so that you can copy and paste them by using the right-click menu. For example, when you copy a wellpath and paste it into a different design, the wellpath that currently exists for the target design is deleted. Well Explorer replaces the old wellpath with the copy of the new one.
Rules for Associating Components
The rules for associating components are listed below.
For Definitive Surveys, Pore Pressure Groups, Fracture Gradient Groups, Geothermal Gradient Groups, Assemblies, and Hole Sections:
• Each component can only be associated with one design or case.
• When one component is copied and pasted, an actual copy is made.
• When one component is pasted, the component it replaces will be deleted (unless it is locked).
• If the destination for the paste is locked (Design or Case) or the item to be replaced is locked, a message appears and the paste is not completed.
• If the design is locked, all of its associated items are also locked.
COMPASS™ Software Release 5000.1.7 Training Manual 2-7 Chapter 2: The Engineer’s Data Model (EDM™) Database
For Fluids:
• When a fluid is copied and pasted, an actual copy is made.
• When a fluid is pasted, the one it replaces will not be deleted.
• Fluids can only be deleted by using the Fluid Editor in the WELLPLAN software.
• If the destination case is locked or the fluid to be replaced is locked, a message appears and the paste is not completed.
Chapter 2: The Engineer’s Data Model (EDM™) Database