Ghawar (Arabic:الغوار) is an
oil fieldAn oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...
in
Saudi ArabiaSaudi Arabia , is an Arab country and the largest country of the Arabian Peninsula. It is bordered by Jordan on the northwest, Iraq on the north and northeast, Kuwait, Qatar, Bahrain, and the United Arab Emirates on the east, Oman on the southeast, and Yemen on the south...
. It is located about WSW from the city of
DhahranDhahran is located in Saudi Arabia's Eastern Province, and is a major administrative center for the Saudi oil industry. Large oil reserves were first identified in the Dhahran area in 1931, and in 1935 Standard Oil of California drilled the first commercially viable oil well...
in
Al-AhsaAl-Ahsa may refer to:* Al-Ahsa or Al-Hasa - an oasis region in eastern Saudi Arabia* Al-Ahsa Governorate - the administrative unit that includes the Al-Ahsa oasis...
county of the Eastern Province. Measuring , it is by far the largest conventional oil field in the world. The field is entirely owned and operated by
Saudi AramcoSaudi Aramco is the state-owned national oil company of Saudi Arabia. It is the largest oil corporation in the world with the largest proven crude oil reserves and production. Headquartered in Dhahran, Saudi Arabia, Saudi Aramco also operates the world's largest single hydrocarbon network, the...
, the nationalized Saudi oil company. Relatively little is known about Ghawar because the company and Saudi government closely guard field performance information and per-field production details.
Ghawar (Arabic:الغوار) is an
oil fieldAn oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...
in
Saudi ArabiaSaudi Arabia , is an Arab country and the largest country of the Arabian Peninsula. It is bordered by Jordan on the northwest, Iraq on the north and northeast, Kuwait, Qatar, Bahrain, and the United Arab Emirates on the east, Oman on the southeast, and Yemen on the south...
. It is located about WSW from the city of
DhahranDhahran is located in Saudi Arabia's Eastern Province, and is a major administrative center for the Saudi oil industry. Large oil reserves were first identified in the Dhahran area in 1931, and in 1935 Standard Oil of California drilled the first commercially viable oil well...
in
Al-AhsaAl-Ahsa may refer to:* Al-Ahsa or Al-Hasa - an oasis region in eastern Saudi Arabia* Al-Ahsa Governorate - the administrative unit that includes the Al-Ahsa oasis...
county of the Eastern Province. Measuring , it is by far the largest conventional oil field in the world. The field is entirely owned and operated by
Saudi AramcoSaudi Aramco is the state-owned national oil company of Saudi Arabia. It is the largest oil corporation in the world with the largest proven crude oil reserves and production. Headquartered in Dhahran, Saudi Arabia, Saudi Aramco also operates the world's largest single hydrocarbon network, the...
, the nationalized Saudi oil company. Relatively little is known about Ghawar because the company and Saudi government closely guard field performance information and per-field production details. Available information is predominantly historical (pre-nationalization), from incidental technical publications, or anecdotal.
Geology
Ghawar occupies an
anticlineIn structural geology, an anticline is a fold that is convex up and has its oldest beds at its core. The term is not to be confused with antiform, which is a purely descriptive term for any fold that is convex up. Therefore if age relationships In structural geology, an anticline is a fold that is...
above a basement fault block dating to
CarboniferousThe Carboniferous is a geologic period and system that extends from the end of the Devonian period, about 359.2 ± 2.5 Ma , to the beginning of the Permian period, about 299.0 ± 0.8 Ma ....
time, about 320 million years ago;
CretaceousThe Cretaceous , Latin language for "chalky", usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago . In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period of the...
tectonic activity, as the northeast margin of Africa began to impinge on southwest Asia, enhanced the structure. Reservoir rocks are
JurassicThe Jurassic is a geologic period and system that extends from about Ma to Ma, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the "Age of Reptiles". The start of the period is marked by...
Arab-D limestones with exceptional porosity (as much as 35% of the rock in places),
sourcedIn petroleum geology, source rock refers to rocks from which hydrocarbons have been generated or are capable of being generated. They form one of the necessary elements of a working hydrocarbon system. They are organic rich sediments that may have been deposited in a variety of environments...
from the Jurassic Hanifa formation, a marine shelf deposit of mud and lime with as much as 5% organic material (1% to 2% is considered good oil source rock). The seal is an
evaporiticEvaporites are water-soluble mineral sediments that result from the evaporation of bodies of surficial water. Evaporites are considered sedimentary rocks.- Formation of evaporite rocks :...
package of rocks including impermeable
anhydriteAnhydrite is a mineral - anhydrous calcium sulfate, CaSO
4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from...
.
History
Historically, Ghawar has been subdivided into five production areas, from north to south, 'Ain Dar and Shedgum, 'Uthmaniyah, Hawiyah and Haradh. The major oasis of
Al-AhsaAl-Ahsa may refer to:* Al-Ahsa or Al-Hasa - an oasis region in eastern Saudi Arabia* Al-Ahsa Governorate - the administrative unit that includes the Al-Ahsa oasis...
and the city of Al-Hofuf are located on Ghawar's east flank, corresponding to the 'Uthmaniyah production area. Ghawar was discovered in 1948 and put on stream in 1951. Some sources claim Ghawar
peakedPeak oil is the point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. The concept is based on the observed production rates of individual oil wells, and the combined production rate of a field of related oil wells...
in 2005, though this is strongly contested by the field operators.
Saudi Arabia's own oil company (
Saudi AramcoSaudi Aramco is the state-owned national oil company of Saudi Arabia. It is the largest oil corporation in the world with the largest proven crude oil reserves and production. Headquartered in Dhahran, Saudi Arabia, Saudi Aramco also operates the world's largest single hydrocarbon network, the...
) reports that Ghawar has produced 48% of its proven reserves
Production
Approximately 60-65% of all Saudi
oilPetroleum or crude oil is a naturally occurring, flammable liquid found in rock formations in the Earth consisting of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds.The term "petroleum" was first used in the treatise De Natura Fossilium, published in...
produced between 1948 and 2000 came from Ghawar. Cumulative production to the end of 2005 was about . Currently, Ghawar is estimated to produce over of oil a day (6.25% of global production).
Ghawar also produces approximately of natural gas per day.
Field Reserves
Saudi AramcoSaudi Aramco is the state-owned national oil company of Saudi Arabia. It is the largest oil corporation in the world with the largest proven crude oil reserves and production. Headquartered in Dhahran, Saudi Arabia, Saudi Aramco also operates the world's largest single hydrocarbon network, the...
has stated that it has more than of proven reserves remaining.
Matthew SimmonsMatthew Simmons, chairman and CEO of Simmons & Company International, is a prominent oil-industry insider and one of the world's leading experts on the topic of peak oil. Simmons was motivated by the 1973 energy crisis to create an investment banking firm catering to oil companies. In his previous...
, in his book
Twilight in the Desert, suggests that production from the Ghawar field and Saudi Arabia may soon
peakThe Hubbert peak theory posits that for any given geographical area, from an individual oil-producing region to the planet as a whole, the rate of petroleum production tends to follow a bell-shaped curve...
.
When appraised in the 1970s, the field was assessed to have of original oil in place, with about recoverable (1975 Aramco estimate quoted by Matt Simmons). The second figure, at least, was understated, since that production figure has already been exceeded.
External links