Wafer Check Valve

Wafer Check Valve

Definition(s)

Wafer Check Valve

Variety of check valve that has a two-piece disk, hinged down the diameter of the pipe. Flow pushes the valve into the open position. When there is no flow, a spring pushes the disk shut to prevent back flow. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Wall-Heating

Wall-Heating

Definition(s)

Wall-Heating

In non-reactive systems subjected to an external fire, boiling occurs at or near the walls of the vessel, commonly referred to as wall-heating. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global Standards  
Warm-Up Time

Warm-Up Time

Definition(s)

Warm-Up Time (not applicable to spot-reading apparatus) (times)

Time interval, with the apparatus in a stated atmosphere, between the time when the apparatus is switched on and the time when the indication reaches and remains within the stated tolerances (see Figures 1 and 2). Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global Standards
WAT

WAT

Definition(s)

WAT

Wax appearance temperature. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards  
Watch circle

Watch circle

Definition(s)

Watch circle

Area of predetermined size in which the drilling rig maintains its intended position (station) in order to not exceed equipment or reaction time limitations. NOTE If the rig moves to the edge of the watch circle, then attention is heightened. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards  

Watch circle

The rig offset perimeter around the well location for which special procedures are to be initiated to prepare to disconnect the drilling riser or actually implement the disconnect to prevent damage due to excessive offset. Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global Standards  
Water Availability

Water Availability

Definition(s)

Water Availability

The hydrologic capacity of a water source (surface water body, groundwater, municipal water) to sustain additional water demands after considering other current water uses and water conditions. (GEMI, 2012) Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Balance

Water Balance

Definition(s)

Water Balance

The relationship between input and output of water across a defined system boundary, e.g. a watershed or the project site boundary. If input > output, then storage within the system increases; if input < output, then storage decreases. (DRET, 2008). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Consumption

Water Consumption

Definition(s)

Water Consumption

The difference between water withdrawal and water discharge to/from the same source (or watershed). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Demand

Water Demand

Definition(s)

Water Demand

The total water requirements of a project. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Depth

Water Depth

Definition(s)

Water Depth

vertical distance between the sea floor and still water level. NOTE 1 As there are several options for the still water level (see 3.35), there can be several water depth values. Generally, design water depth is determined to LAT or to mean sea level. NOTE 2 The water depth used for calculating wave kinematics varies between the maximum water depth of the highest astronomical tide plus a positive storm surge, and the minimum water depth of the lowest astronomical tide less a negative storm surge, where applicable. The same maximum and minimum water depths are applicable to bottom founded and floating structures, although water depth is usually a much less important parameter for floating structures. Water depth is, however, important for the design and analysis of the mooring system and risers for floating structures. Source: API RP 2MET, Derivation of Metocean Design and Operating Conditions, First Edition, November 2014. Global Standards

Water Depth

Vertical distance between the sea floor and still water level. NOTE 1 As there are several options for the still water level (see A.6.4.4), there can be several water depth values. Generally, assessment water depth is determined to the extreme still water level. NOTE 2 The water depth used for calculating wave kinematics varies between the maximum water depth of the mean high water spring tide plus a positive storm surge, and the minimum water depth of the mean low water spring tide less a negative storm surge, where applicable. NOTE 3 Adapted from ISO 19901-1:2005, definition 3.41. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards
Water Discharge

Water Discharge

Definition(s)

Water Discharge

Water effluents discharged outside a reporting organization boundary to subsurface waters, surface waters, sewers that lead to rivers, oceans, lakes, wetlands, treatment facilities, and groundwater. (GEMI, 2012) Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Governance

Water Governance

Definition(s)

Water Governance

Encompasses the internal and external mechanisms by which the water related aspects of an entity are controlled and by which the entity is accountable to its stakeholders, including which decisions are made, how and by whom. It defines the relationships between different stakeholders and between different parts of the system. The term governance applies to all entities and is distinct from the term government. (AWS, 2013, adapted from ISEAL Alliance, 2007: ISEAL Emerging Initiatives Module 4: Models of Governance, July 2007.). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Hammer

Water Hammer

Definition(s)

Water Hammer

Shock load or high-pressure surge caused by sudden halting of flow in a pipeline or piping system. Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global Standards

Water Hammer

Pressure wave created by the rapid closing of a valve on a flowing line or vessel. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Water Intensity

Water Intensity

Definition(s)

Water Intensity

The ratio between water intake and a defined unit of production. (Organisation for Economic Co-operation and Development). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Quality

Water Quality

Definition(s)

Water Quality

The quality of a specific water body is defined by the suitability or condition of the water for a particular use based on its physical, chemical, and biological characteristics. (GEMI, 2012). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Scarcity

Water Scarcity

Definition(s)

Water Scarcity

The point at which the aggregate impact of all users impinges on the supply or quality of water under prevailing institutional arrangements to the extent that the demand by all sectors, including the environment, cannot be satisfied fully (United Nations, 2006). One measure is the Falkenmark Indicator, which defines water security as when annual water supplies in a country or region drop below 1,000 cubic metres per person per year. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Seal

Water Seal

Definition(s)

Water Seal

Device that directs the flow of relief gases through a liquid (normally water) on the path to the flare burner, used to protect the flare header from air infiltration or flashback, to divert flow, or to create backpressure for the flare header.

Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards
Water Security

Water Security

Definition(s)

Water Security

The reliable availability of an acceptable quantity and quality of water for health, livelihoods and production, coupled with an acceptable level of water-related risks. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Stewardship

Water Stewardship

Definition(s)

Water Stewardship

Use of water that is socially beneficial, environmentally responsible and economically sustainable. (AWS, 2013. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Storage Unit

Water Storage Unit

Definition(s)

Water Storage Unit

Any body in which water collects and resides for a period of time, e.g. the atmosphere, ponds, lakes, oceans, aquifers, etc. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Stress

Water Stress

Definition(s)

Water Stress

Occurs when the demand for water exceeds the available amount of water over a given period, or when the poor quality of available water restricts its use (AWS, 2013). Leflaive et al. (2012) explain that water stress can be quantified by taking a ratio of water demand to water availability, and define four categories of water stress ranging from ‘no stress’ to ‘severe stress’ based on these ratios. Another measure is the Falkenmark Indicator, which defines water stress as when annual water supplies in a country or region drop below 1,700 cubic metres per person per year (United Nations). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Table

Water Table

Definition(s)

Water Table

The upper surface of groundwater. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water Withdrawal

Water Withdrawal

Definition(s)

Water Withdrawal

The sum of all water drawn into the boundaries of the reporting organization from external sources. (GEMI, 2012). Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Water-Based Drilling Fluid

Water-Based Drilling Fluid

Definition(s)

Water-Based Drilling Fluid

Drilling fluid in which water is the suspending medium for solids and is the continuous phase, whether oil is present or not. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Water-Based Hydraulic Fluid

Water-Based Hydraulic Fluid

Definition(s)

Water-Based Hydraulic Fluid

A control liquid mixture composed mainly of water with additives to provide lubricity, anti-foaming, anti-freeze, anti-corrosion and anti-bacterial characteristics. Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global Standards
Water-Wetting Capability

Water-Wetting Capability

Definition(s)

Water-Wetting Capability

Capability of a fluid to alter the quality or state of being water-wetted. NOTE A fully water-wet state is considered most desirable to provide cement bonding. Source: API RP 10B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005 (Reaffirmed: July 2010). Global Standards
Watershed

Watershed

Definition(s)

Watershed

The hydrologic divide between drainage basins. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards
Watertight

Watertight

Definition(s)

Watertight

Watertight means designed and constructed to withstand a static head of water without any leakage, except that watertight equipment means enclosed equipment so constructed that a stream of water from a hose (not less than 1 inch in diameter) under head of about 35 feet from a distance of about 10 feet, and for a period of 5 minutes, can be played on the apparatus without leakage. Source: Mobile Offshore Drilling Units, 46 CFR 107-109 (2013). Regulations  

Water-tight

Equipment so enclosed that it meets at least a NEMA 250 Type 4 or 4X or an IEC IP 55 or 56 rating. Source: API RP 14F, Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class 1, Division 1 and Division 2 Locations, Fifth Edition, July 2008. Global Standards  

Watertight

Watertight means the capability of preventing the passage of water through the structure in any direction under a head of water for which the surrounding structure is designed. Source: IMO Resolution A.1023(26), Code for the Construction and Equipment of Mobile Offshore Drilling Units (2009 MODU Code), 2009. Global Standards  

Watertight

“Watertight” means designed and constructed to withstand a static head of water without any leakage (étanche à l’eau). Source: Canada Oil and Gas Installations Regulations, SOR/96-111, Canada, current to May 1, 2014. Regulations Source: Canada Oil and Gas Installations Regulations, SOR/96-118, February 2013. Regulations Source: Nova Scotia Offshore Petroleum Installations Regulations, SOR/95-191, Canada, current to May 31, 2012. Regulations  

Watertight

Watertight. Watertight means capable of preventing the passage of water through the structure in either direction with a proper margin of resistance under the pressure due to the maximum head of water which it might have to sustain.  <Chapter I, regulation 3>. Source: IMO Resolution MSC.143(77), amendments to Annex B to the 1988 Load Lines Protocol, 5 June 2003, International Maritime Organization. Legislation  

Watertight

Watertight means having scantlings and arrangements capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions. In the damaged condition, the head of water is to be considered in the worst situation at equilibrium, including intermediate stages of flooding. . <Chapter II-1, regulation 2>. Source: IMO Resolution MSC.216(82), amendments to the International Convention for the Safety of Life at Sea, 1974, as amended, 8 December 2006, International Maritime Organization. Legislation  

Watertight

A closing appliance is considered watertight if it is designed to prevent the passage of water in either direction under a head of water for which the surrounding structure is designed. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards  
Wave Frequency Motion

Wave Frequency Motion

Definition(s)

Wave Frequency Motion

Motion of the vessel at the frequencies of incident waves. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards
Wave Scatter Diagram

Wave Scatter Diagram

Definition(s)

Wave Scatter Diagram

Table listing occurrence of sea-states in terms of significant wave height and wave peak period or mean upcrossing period. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards