Glossary - Energistics

Glossary

PRODML™ Enabling Production Operations, Optimization, Reporting and Data Management for the Exploration and Production (E&P) Domain.

Version: PRODML Version 1.1

Abstract This document specifies the glossary for PRODML Version 1.1.

Prepared by: Energistics and the PRODML SIG

Date published: 6 March 2009

Document type: Specification

Keywords: web services, production, interoperability

Glossary - PRODML Version 1.1

Document Information

DOCUMENT VERSION: 1.1

DATE: 6 March 2009

Technical Color: R: 210 G:124, B50

Language US English

This document was produced by Energistics and the PRODML SIG

Energistics™, POSC®, Epicentre®, WITSML™, PRODML™, Upstream Standards. Bottom Line Results.™, The Energy Standards Resource Centre™ and their logos are trademarks or registered trademarks of Energistics. Access, receipt, and/or use of these documents and all Energistics materials are generally available to the public and are specifically governed by the Energistics Product Licensing Agreement (http://www.energistics.org/posc/Product_License_Agreement.asp)

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http://www.energistics.org/posc/Product_License_Agreement.asp


Amendment History

Version Date Comment By

V1.1 6 March 2009

Prepared for final release. Gary Masters

V1.1 Dec 2008 Release V 1.1 Robin Getty

V1.0 11/10/2006 Release to Public Cheryl Dugger

RC_1.0 8/30/06 Release Candidate for Industry Review Cheryl Dugger

0.91 08/24/2006 Added Documentation Mapping Jerry Blaker

0.80 08/21/2006 Create First Draft Jerry Blaker

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Table of Contents

Preface 5 1. Document Overview 6

1.1 Document Aims 6 1.2 PRODML Documentation 6

2. Index of Glossary Entries 8 3. Glossary Entries 10

Index of Figures Figure 1: Influences on PRODML Version 1.1 Standards 5 Figure 2: PRODML Documentation Overview 6

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Preface PRODML™ is the Energistics' family of energy industry web services and data exchange standards for the Production domain. The purpose of PRODML is to enable increased innovation in the composition of optimization solutions for an increasingly complex production systems while reducing cost and risk. This translates into enabling the development of plug compatible service components and associated clients by energy sector vendors as well as energy companies.

PRODML forms a framework within which energy companies can configure and achieve simple or complex processes related to operations, optimization, reporting, and/or information management. The PRODML Standards were developed by Energistics and the PRODML Special interest Group, which is comprised of energy companies and vendors and facilitated by Energistics.

The PRODML Standards Version 1.0 were released in November 2006 and focused on production optimization processes that consider activity starting from the reservoir-wellbore boundary and progressing to the custody transfer point and for production optimization recommendations that can be put into effect within one day. The nature of Version 1.0 was based on the widely used Energistics family of drilling standards, WITSML, that was first published in 2001. PRODML reused many of WITSML's data structures and interface operations. PRODML Version 1.0 was also based on an extension to WITSML developed in 2004 to support production reporting. It adopted current best practices for interface definition as defined by IT industry organizations, such as WS-I and W3C.

This version of PRODML (Version 1.1) was released in March 2009. It represents an incremental evolution of Version 1.0 and includes enhancements derived from the experience of adapting PRODML Version 1.0 for use in six pilot implementations during 2007.

PRODML 1.1

Experience of Using

PRODML V1.0

Scope of PRODML Standards

EnergisticsEnergy Industry Web Services Interoperability

Standards

Figure 1: Influences on PRODML Version 1.1 Standards

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1. Document Overview

1.1 Document Aims The intent of the glossary is to provide the reader, whether a business person, IT specialist, or future implementer of PRODML, with a source of understanding of key terminology within the relevance of PRODML.

1.2 PRODML Documentation The documentation for PRODML is organized as follows:

Purpose Use &

Evolution

PRODMLReference

Architecture

ServiceSpecifications

DataSpecifications

Documents

Courseware

Pilots

Sample Code

Reference Implementations

Courseware

Code

VersionHistory

FutureDirection

Glossary

WSDL Files

ProgrammersGuide

Energy Industry Web Services Interoperability

Standards

Figure 2: PRODML Documentation Overview

• Glossary (THIS DOCUMENT) Defines terms used in the PRODML documentation

• Reference Architecture Describes the PRODML architecture.

• Purpose, Intended Use and Evolution of the Standard Provides a discussion of the business case and typical use-cases for PRODML.

• Future Directions Defines the areas that and directions that the PRODML Standards are likely to cover in future

• Data Specifications Specifies the data covered by PRODML operations in terms of schemas

• Service Specifications Specifies the web service contracts that are part of PRODML

• Programmers Guide Provides guidance on the implementation and use of PRODML services.

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The intended audiences of the PRODML documentation set is illustrated below:

USE KEY

A= PRIMARY DOCUMENT Key document to read B=SECONDARY DOCUMENT Good material to review C= LESS USEFUL Review as needed IM

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Purpose, Use & Evolution A A A A A B B Reference Architecture C C A A A B B Service Specifications C C B B C A B Data Specifications C B C B B B A Energy Industry Web Services Interop Standards C C C A A A B PRODML Glossary B B B B B B B PRODML Tool Kit C C C C B A C Recommendations and Future Directions C B B A B C A

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2. Index of Glossary Entries Abstraction Layer 10 Advisory Tool 10 API 10 API Specification 10 Architectural Abstraction 10 Architecture 10 Asset Hierarchy 10 Asset Model 10 Asynchronous 10 Attribute 10 Basic Authentication 10 Business Objects 11 Closed-Loop Optimization 11 COM 11 Component Workflows 11 Controlling Application 11 CRUD 11 Data Consolidator 11 Data Integrator 11 Data Objects 11 Data Quality Attributes 11 Data Schema 12 DCOM 12 Flow Unit 12 Function/Method/Interface 12 Gas Lift Optimization Applications 12 Gas Lift Well Models 12 Historian 12 HTTP/S 12 Hydrocarbon Flow 12 Intelligent/Smart Well Optimization 12 Metadata 12 Model 13 Model Management 13 Model-Based Asset 13 Network 13 Node 13 Non-Functional Requirements 13 Non-Repudiation 13 Notification 13 OASIS 13 OPC 13 OPC-UA 14 Open-Loop Optimization 14 Operations Flow 14 Operator (in PRODML context) 14 Optimizer 14 Orchestration Applications 14 Performance & Intended Use & Evolution of the Standard 14 Persistent Data Store 14 Plug and Play (in context of PRODML) 14 Port 15

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POSC 15 PRODML 15 PRODML GUID 15 PRODML URI 15 PRODML Workgroup 15 PRODML Tool Kit 15 Production Asset: 16 Production Monitoring 16 Production Optimization 16 Production Asset: 16 Publish /Subscribe (pub/sub) 16 Pull 16 Push 16 Real Time Gas Lift Optimization 16 Reference Architecture (PRODML) 16 Schema 17 Service Oriented Architecture 17 Shared Asset Model 17 SIG (PRODML) 17 SLA 17 SOAP 17 SQL 17 SSL 17 Stateless services 18 Synchronous 18 Tag 18 Time-Series Data 18 Unit 18 URI 18 UTC 18 Vendor (in PRODML context) 18 W3C 18 Web Service 18 Wire Level Security 19 WITSML 19 Wrapper 19 WS-*Stack 19 WS-I 19

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3. Glossary Entries Abstraction Layer

Software that resides between the inner details of some individual resource and any external entity that may want to use that resource.

Advisory Tool

An application that presents and / or pushes messages and associated information to assigned users. Used to trigger the decision-making portion of the optimization cycle, both for normal changes in operations settings and for intervention.

API

Application Program Interface. A set of calling conventions defining how a service is invoked through a software package.

API Specification

A very detailed definition of the interface and interaction functionality along with usage and implementation guidance.

Architectural Abstraction

Definitions, abstract models, schemas, and protocols that underlie the definition of a service. An architectural abstraction is a deterministic encoded representation of reality that can be assumed by software to represent normal behavior.

Architecture

The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them. (Software Architecture in Practice (2nd edition) - Bass, Clements, Kazman; Addison-Wesley 2003)

Asset Hierarchy

A term used to refer to a hierarchy that organizes the equipment associated with an asset.

Asset Model

Either: A virtual manifestation of all or, part of a production process achieved by a combination of mathematics and process logic. See "Model-Based Asset"

Example: A well model that mathematically describes the flow behavior of process fluid from the well bore to the surface wing valve e.g. Prosper from PETEX.

Or: A term used to refer to a computer based representation of a Production Asset that contains (among other things) representations of Productions Components and various relationships between them.

Asynchronous

An interaction is said to be asynchronous if the participating agents are not available to rendezvous while the associated message is sent/received and processed.

Example: E-mail messages, letters sent in the mail, voicemail, etc.

Attribute

A single property of a data object. An object is described by the values of its attributes. In the Flow Unit context, information of the Unit that is not transferred into or out of the Flow unit.

Example: See Flow Unit

Basic Authentication

The Basic Authentication scheme is a method designed to allow a web browser or other client program to provide credentials, in the form of a user name and password, when making a request. In Basic

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Authentication, credentials are passed as plain text and if intercepted can be easily read. The scheme also provides no protection for any information passed back from the server.

Encryption based protocols such as SSL provide methods to (reasonably) securely encrypt Data passed during a Basic Authentication discussion.

Business Objects

Objects in an object-oriented computer program that abstracts the entities in the domain that the Program is written to represent. Good business objects will encapsulate all of the data and Behavior associated with the entity that it represents.

Closed-Loop Optimization

A business process that can completely change equipment settings automatically, subject to targets and constraints that can be changed by applications and users. In production optimization, this is often used for smaller examples of artificial lift, such as beam pump and gas lift, but is almost never used for larger examples such as water flood and field-wide optimization.

COM

Component Object Model. Microsoft's proprietary object-oriented programming model used to enable inter-process communication and dynamic object creation. It has been deprecated in favor of .Net.

Component Workflows

Component Workflows are methods that are used to construct and maintain the software models. These workflows include steps to improve data quality, test the model stability and accuracy, and where possible test the model flexibility over a range of data values.

Controlling Application

Any application within which a logical business process can be represented - either with lines of code or via a graphical interface - and then can execute this process using one or more PRODML services. A Controlling Application may have the built-in ability to initiate a process (by monitoring a flow of data for changes or at a pre-defined time), or it may be initiated by an external application.

CRUD

Acronym for standard database functionality of Create, Read, Update, Delete. In the PRODML context, CRUD actions require a unique key to identify the specific data element the action is to be taken on.

Data Consolidator

1. An application that gathers and assembles data from different applications/databases.

2. Data Consolidator organizes aggregates and renames data to provide a centralized and consistent method for a variety of information exchanges.

Example: OSIsoft PI Invensys Romeo. These are used to integrate data from various sources and in various formats and structures and they are often used to orchestrate functions for data quality management and time-based analytics.

Data Integrator

See 'Data Consolidator'

Data Objects

A PRODML data object represents a highly related grouping of data items. The business concept represented by the object must have business identity and the identity of the data items contained within the object should be unique within the context of the object. That is, the object provides context for the details. The object may itself be unique within the context of another object and is typically related to capturing the results of a higher level activity.

Example: Example concepts would be a well log, an operations report, a bottom hole assembly, a measurement set.

Data Quality Attributes

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Information that describes the origin, quality, time and type of data.

Example: A data element can be measured or derived, have good or bad quality etc.

Data Schema

A formal description of the structure of data.

DCOM

Distributed Component Object Model. A Microsoft proprietary technology for software components distributed across several networked computers. It is descended from COM, which connects components on a single machine, and later part of COM+. It has been deprecated in favor of Microsoft .NET.

Flow Unit

Objects that represent an organization of equipment and its associated information. This is a type of “system” in port-based modeling theory.

Function/Method/Interface

The end-points of a service within which the functionality is defined.

Gas Lift Optimization Applications

These are systems specifically designed to monitor, control and optimize the gas lift process.

Example: Case Gaslift, FieldWare GasLift.

Gas Lift Well Models

These are individual well simulations that model the gas/liquid two phase flow characteristics from sand-face to surface wing-valve. Outputs from these models are as follows:

- Graphs of pressure and temperature vs. depth. Graphs can be used to analyze gas lift valve and tubing performance

- Optimal gas lift gas injection rates for a given bulk supply rate

Example: Prosper, Wellflow, WinGLUE.

Historian

Software that records, stores, organizes, processes and presents a set of time series of real-time data as historical trends.

Example: OSIsoft PI, Yokogawa Exaquantum, Honeywell PHD, Invensys Historian, Aspentech Infoplus.

HTTP/S

HTTPS (or HTTP over SSL [Secure Sockets Layer]) is a Web protocol that encrypts data to ensure that it cannot be changed while in transit without the client or server being aware that the data stream has been interfered with.

Hydrocarbon Flow

A hydrocarbon flow is a physical flow - it follows a physical arrangement of equipment.

Example: Gas lift optimization is a hydrocarbon flow because it includes additional equipment to inject gas into the reservoir. Other hydrocarbon flows include free-flowing wells, ESP wells etc.

Related definitions: "Operations Flow"

Intelligent/Smart Well Optimization

Maximization of overall production of a well that has subsurface instruments and may have subsurface valves, subject to targets and constraints. This type of optimization handles the adaptation of well operation to handle constraints of segments of the well structure, which may include zones within an individual tubing string.

Metadata

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Data that are used to describe other data. For example, metadata may describe how and when or by whom a particular set of data was collected and how the data are formatted. The distinction between data and metadata is not absolute and may depend of context; the same information may sometimes be viewed as either data or metadata, depending on how it is being used.

Model

1. An abstraction of reality useful in communications and in problem definition and decomposition.

2. These are used to model behaviors of equipment, fluids and occasionally the reservoirs, and they infer component flow rates, system pressures, and operating and constraint gradients such

Example: Data Models; Simulation Models; Collection of networks

Model Management

A way to monitor simulation accuracy by comparing the simulation to alternate approaches. In production optimization, this can be done by comparing forward models (such as for wells) with a group of models that are used to backward allocate well performance.

Model-Based Asset

As in model-based asset operations: Model is a representation of equipment and fluids. Models are created from a mass of data, equations and computations that mimic the actions of things represented.

Network

A collection of connected units.

Node

Allows ports to connect in a network.

Non-Functional Requirements

The qualities we desire of a problem solution other than those concerning its functionality; e.g. its robustness, its efficiency, its security, its extensibility, its maintainability, its portability, etc.

Non-Repudiation

A method by which the sender of data is provided with proof of delivery and the recipient is assured of the sender's identity, so that neither can later deny having processed the data.

Example: Post Office letter registration

Notification

A concept that allows event-driven programming between web services. The consumer's 'notify' method is invoked every time a notification is available on a topic, to which they have subscribed, and that notification has passed from the producer.

OASIS

The Organization for the Advancement of Structured Information Standards, a global consortium that develops data representation standards for use in computer software. Responsible for the definition of standards such as WS-Security.

OPC

A standard mechanism for communicating to numerous data sources, either devices on the factory floor or a database in a control room is the motivation for OPC.

Example:

Field Management: With the advent of “smart” field devices, a wealth of information can be provided concerning field devices that was not previously available. This information provides data on the health of a device, its configuration parameters, materials of construction, etc. All this information must be presented to the user, and any applications using it, in a consistent manner.

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Process Management: The installation of Distributed Control Systems (DCS) and SCADA systems to monitor and control manufacturing processes makes data available electronically which had been gathered manually.

Business Management: Benefits can be gained by installing the control systems. This is accomplished by integrating the information collected from the process into the business systems managing the financial aspects of the manufacturing process. Providing this information in a consistent manner to client applications minimizes the effort required to provide this integration.

OPC-UA

OPC-UA (OPC Unified Architecture) is the next generation OPC solution based on a web services approach. The OPC-UA specifications are in progress and have not been released at this time. PRODML and POSC have signed an agreement that allows access to the OPC-UA work products prior to the release to the public. It is recommended that the PRODML community monitor the work products of OPC-UA and determine what impact it may have on the future evolution of PRODML.

Open-Loop Optimization

A business process that changes equipment settings with partial automation, subject to targets and constraints that can be changed by applications and users. In production optimization, this is often used for larger examples such as water flood and field-wide optimization. The architecture presents a set of recommendations to users, who accept, modify or reject these, and the architecture implements the users’ decisions.

Operations Flow

An operations flow is a workflow - it can follow a physical arrangement of equipment or an activity across like equipment. Model and data quality management, and production volumes are operations flows. Both of these can work with any combination of hydrocarbon flows.

Related Definitions: "Hydrocarbon Flow"

Operator (in PRODML context)

Used as an umbrella term to describe the organization that uses a PRODML instance.

Optimizer

This is used to calculate the proposed changes in controlled variables subject to the given data of constraints, measured variables and targets, to move as close as possible to the given objective function. Almost all optimizers are steady-state, which means that they cannot process time-based transitions by themselves.

Orchestration Applications

Any application within which a logical business process can be represented - either with lines of code or via a graphical interface - and then can execute this process using one or more PRODML services.

Performance & Intended Use & Evolution of the Standard

Discussion document indicating the appropriate use of the V1.0 PRODML standard. Explains where it could be applied and instances where use is not recommended. Also discusses the ongoing process to evolve the standard to support wider use.

Persistent Data Store

A server that supports the PRODML API and that also supports data persistence and data management.

Example: A 'wrapped historian' is an example of a persistent data store, whether data management functions are available through the PRODML API or not.

Further, the following are NOT persistent data stores:- a transient application that is invocable through the PRODML API- a productVolume XML file or collection of productVolume XML files

Plug and Play (in context of PRODML)

Within a PRODML enabled workflow, the standard is designed to support interaction between software components from different vendors in a consistent way. These interactions are a combination of requests

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for services and responses to these requests, for example the supply of requested data. Within this context “Plug and Play” means that the services and data interactions are sufficiently well defined and implemented such that it is possible to exchange one vendor’s product with a functionally comparable product from another vendor and still maintain the overall integrity of the workflow, notwithstanding differences in underlying technical algorithms or correlations etc. Note that in this context “Plug and Play” does not imply a self-configuring system where new components are recognized and necessary adjustments made to accommodate them.

Within a PRODML enabled workflow the interactions between component applications are sufficiently well defined such that it should be possible to replace a product from one vendor with a broadly equivalent offering from another without disrupting the workflow. This requires that the services and data exchanges involved in the workflow are adequately defined by the standard and implemented in a consistent manner in both products.

Port

A port is a connection in a Flow unit where information is exchanged. This is a ‘port” of port-based modeling theory.

Example: Allows flows in and out.

POSC

Petrotechnical Open Standards Consortium. POSC is an international, not-for-profit, membership organization which facilitates the development and maintenance of open standards for improving E&P business performance in the integration of oil and gas business processes. More information can be found at www.posc.org

PRODML

PRODuction xML An emerging standard specification for the exchange of Production data using XML.

Example: Data Transport of XML to applications in support of Gas Lift optimization.

PRODML GUID

A PRODML GUID is any GUID (as defined by [RFC 4122]) that identifies a production component in a PRODML installation. The GUID may or may not be generated or ‘owned’ by a PRODML server, so long as it conforms to the standard for a GUID. Naturally, the GUID can be written several ways, including in its canonical form, as a URN in the UUID namespace, and as a PRODML URI. For the purposes of this document, when we speak of a PRODML GUID, we mean a PRODML GUID formatted as a PRODML URI. A PRODML GUID looks like this:

prodml:[//authority]/guid/f81d4fae-7dec-11d0-a765-00a0c91e6bf6

The square brackets are not actually part of the string; they indicate that the authority is optional. So a PRODML GUID is a PRODML URI that contains two path components: the naming-system ‘guid’ and the identifier, being the guid itself in canonical form.

PRODML GUIDs were previously known as PRODML IDs.

PRODML URI

A PRODML URI is any URI that uses the PRODML URI scheme. Practically, this means a sequence of characters that begins with the string “prodml:”. The scheme-specific string that follows this prefix uniquely defines a component in a PRODML installation. It may or may not be a GUID. It has the form:

prodml:[//authority]/path

The square brackets indicate that the authority is optional.

PRODML Workgroup

The initial development of the standard was accomplished in approximately one year by an industry workgroup comprised of five energy companies, eight software providers and a standards organization.

PRODML Tool Kit

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http://www.posc.org/

http://tools.ietf.org/html/rfc4122


Comprehensive ‘developer quick start’ documentation with examples and code-fragments intended to help start up a compliant Client or Server.

Production Asset:

A term used in this context to refer to a collection of physical production equipment and pipes organized into different areas. It is used to refer to a whole production system or a part thereof. Other usages associate the term with a producing field with, depending on the context, or with out, it’s associated production facilities.

Production Monitoring

The automated surveillance of changes in production behaviors such as a rapid increase in produced water, or a rapid decrease in produced oil while overall flow is relatively constant for a well or set of wells.

Production Optimization

Maximizing the total accumulated profit of producing hydrocarbons within business, safety, environmental and operating constraints, with a close integration and automated processing of data collection, modeling, decision-making and the core optimization calculations in right-time. PRODML is focused on production optimization that can be effected within a day, which excludes capital-intensive options.

The key aspects of this type of optimization are:

- Significant use of automated data quality management to overcome intermittent, drifting and incomplete measured data

- Significant use of models to infer data that is not measurable or not measured by instrumentation

- Use of automated time-based analytics, including forecasting, to compensate for the inertia of the production operation

- Significant use of decision-making functions to handle compromises between naturally conflicting constraints and targets, and to support workflows that are required to make some of the transitions.

- Integration of schedules for facilities maintenance, well work-overs and well tests. Production Asset:

A term used to refer to a collection of physical production equipment and pipes organized into different areas. It is used to refer to a whole production system or a part thereof. Other usages associate the term with a producing field with, depending on the context, or with out, it’s associated production facilities.

Publish /Subscribe (pub/sub)

An asynchronous messaging architecture in which publishers post messages with specific “topics”, rather than sending messages to specific recipients. The messaging system then broadcasts the posted messages to all interested parties (subscribers).

Pull

A content delivery system where the subscribing computer polls the server periodically for new content; the server does not send data/information to the subscribing client un-requested.

Push

A content delivery system where data/information is automatically delivered from a server to a subscriber computer as soon as it is available or triggered by an update which is based upon a predefined set of request parameters outlined by the subscriber.

Real Time Gas Lift Optimization

Process whereby gas lift gas injection rate to each well is continuously adjusted to fulfill an objective function within given constraints. Objective function might be maximizing oil production from all wells using minimum volume of gas lift gas. Constraints might be:- using gas lift gas from a dedicated source- production capped at the available processing capability of the surface well oil, gas and water facilities - no changes to gas lift injection valves- unconstrained water production- economic considerations are not taken into account

Reference Architecture (PRODML)

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A PRODML Document that provides a comprehensive overview of all technical aspects of PRODML and explicitly defines the fundamental industry patterns which are used to implement standard. This document summarizes content from the API and Data Specification documents to allow that 'casual' reader to gain a broad understanding of the PRODML standard without needing to understand the very detailed recommendations in the specifications. It is an abstract framework for understanding significant relationships among the entities that are part of a PRODML of some environment, and for the development of consistent standards or specifications supporting that environment. The reference architecture is based on a small number of unifying concepts and may be used as a basis for education and explaining standards to a non-specialist. It seeks to provide a common semantics that can be used unambiguously across and between different implementations.

Schema

See "Data Schema"

Service Oriented Architecture

A software architecture that defines the use of loosely coupled software services to support the requirements of business processes and software users. In an SOA environment, resources on a network are made available as independent services that can be accessed in a standard way without knowledge of the underlying platform implementation or programming language.

Shared Asset Model

A PRODML Shared Asset Model (SAM) is a single place to go to:

• Obtain asset-related information – a single authoritative source of metadata (identifiers, associations, and state - as opposed to measurement values) about production components associated with a production asset.

• Obtain identifiers for production components that can be used throughout an installation.

• Obtain references to business services that provide additional information for production components

• Select individual components of the production system and to obtain their identifiers.

Shared Asset Model Services provides consumers and maintainers of SAM information with functionality to query and maintain models of production assets that organize metadata about assets in a consistent way.

SIG (PRODML)

A POSC "Special Interest Group". In general a focus group working on a topic of particular interest. In this context the group is operating under the auspices of the POSC organization and guiding the future evolution of the PRODML standard.

SLA

Service Level Agreement It is now typical that service provision and receipt be governed by an agreement of this nature. It must obviously cover many other issues, as well as defining the service itself.

SOAP

A standard for exchanging XML-based messages over a computer network, usually but not exclusively using HTTP. SOAP forms the foundation layer of the web services stack, providing a basic messaging framework that more abstract layers can build on. SOAP originally stood for "Simple Object Access Protocol", but this expansion is now deprecated because true "objects" in the OOP sense are not involved, so SOAP is now understood as an acronym without expansion.

SQL

Structured Query Language - the most popular computer language used to create, modify, retrieve and manipulate data from relational database management systems.

SSL

Secure Sockets Layer. This is a commonly-used protocol for managing the security of a message transmission over the Internet.

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Stateless services

Stateful and stateless are adjectives that describe whether a computer or computer program is designed to note and remember one or more preceding events in a given sequence of interactions with a user, another computer or program, a device, or other outside element. Stateful means the computer or program keeps track of the state of interaction, usually by setting values in a storage field designated for that purpose.

Synchronous

An interaction is said to be synchronous when the participating agents must be available to receive and process the associated messages from the time the interaction is initiated until all messages are actually received or some failure condition is determined. The exact meaning of "available to receive the message" depends on the characteristics of the participating agents (including the transfer protocol it uses); it may, but does not necessarily, imply tight time synchronization, blocking a thread, etc.

Example: Telephone conversation between two persons.

Tag

The data structure in a historian where a stream of time-series data is stored.

Example:

A flow rate from a flowmeter;

A controller’s mode of operation;

Text comments from an operator;

The results of a totalizer or calculation.

Time-Series Data

In PRODML, a time series is a sequence of paired time and value data points representing a single data source. These data points must be at successive monotonically increasing time increments either in the past or in the future and may be measured or computed at uniformly spaced times or at irregular intervals.

Unit

A black box with ports used in the configuration network model.

URI

Uniform Resource Identifier. A formatted string that serves as an identifier for a resource, typically on the Internet.

Example:

In many cases the URI will be a URL (that is, a website address, for example: http://www.PRODML.org).

UTC

Universal Coordinated Time (same as Greenwich Mean Time)

Vendor (in PRODML context)

Typically used to describe an organization or group who create, implement or extend a PRODML Instance. In some user-organization, the vendor may actually be an internal development group, however the term is intended to differentiate the developer organization from the consumer organization.

W3C

The W3C is the definitive body for establishing standards for the World Wide Web.

Web Service

A software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact

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http://www.prodml.org/


with the Web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.

Wire Level Security

Also called Transport layer security, this uses Internet protocols (e.g. HTTPS) to secure the traffic between the Web Service and the client application. Contrast this with message level security, which uses the SOAP headers for security information. Wire-level security is more transparent and easy to use; message level security is better for supporting higher level functions like non-repudiation and messaging intermediaries.

WITSML

Wellsite Information Transfer Standard Markup Language.

A specification for the transfer of Wellsite (Drilling) information using XML. Further, the “right time” seamless flow of well site data between operators and service companies to speed and enhance decision-making.

Wrapper

A data structure or software that contains ("wraps around") other data or software, so that the contained elements can exist in the newer system. The term is often used with component software, where a wrapper is placed around a legacy routine to make it behave like an object.

WS-*Stack

The range of Web Services standards which exist in the IT industry (e.g. WS-Security, WS-Addressing, etc.). Not all WS-* standards are adopted by PRODML.

WS-I

WS-I is an open industry organization chartered to promote Web services interoperability across platforms, operating systems and programming languages. The WS-I basic profile version 1.1, available at: http://www.ws-i.org/Profiles/BasicProfile-1.1-2004-08-24.html

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