Later on, the drilling team struck oil in the first exploration well in the Masjed Soleimanin 1908, while exploration operations continued to discover new reservoirs in other areas. Haftgol, Aghajari, Gachsaran, Paznan, NaftSefid oil blocks as well as Lali, Ahvaz, Binak, Bibi Hakimieh, Maroun and Karanj fields were discovered.

One year after oil recovery from the first oil well in Iran and the discovery of new oil reservoirs and fields, oil exploration, extraction and exports were assigned to foreign countries, and for many years Iranian oil was the source of growth, industrial growth and economic prosperity of Western countries, especially Britain and America. In the meantime, not only did nothing benefit Iran, but it became the source of many disasters and economic, social and political turmoil in the country.

Thanks to the increased political awareness of Iranian people and continued struggles, the process of production from oil and gas reservoirs was partly nationalized. However, the drilling industry remained in the hands of foreign states due to its special features. Even after nationalization of petroleum industry, foreign companies were not ready to lose their key role in this sector. That lasted until 1979.

Over this time, foreign governments struck colonialist agreements in a bid to pillage Iran’s oil resources. With the victory in 1979 of the Islamic Revolution, cultural, social, economic and political entities and subsequently the petroleum and drilling industry experienced fundamental changes. Following the Islamic Revolution and the outbreak of the imposed war on Iran, Iranian technicians and engineers managed to preserve Iran’s oil output capacity even without foreign companies’ assistance.  

For instance, after the revolution until March 2021, National Iranian Drilling Company (NIDC) drilled a total of 4,866 oil and gas wells, including 411 offshore ones. They include 2,467 development wells, 118 appraisal wells, 148 exploration wells and 2,133 workover wells. The drillings total 9,668,811 meters, including 1,884 directional wells measuring 876,914 meters. Furthermore, 37,620 meters of core sampling has been also done.

Meantime, 172,343 operations for providing technical and specialized services have been performed. Before the revolution, more than 40 foreign companies provided such services, but now everything is done in the country.

It is true that the drilling industry in the past decades has always been successful in drilling oil and gas wells and the need for foreign companies in this part of the oil industry has never been felt, but while different countries around the world are looking for technologies and strategies to reduce the time and cost of drilling, in Iran, due to sanctions, many drilling rigs have not been operational due to the lack of some spare parts needed for drilling during the operation, well eruption, pipe blockage and many unexpected events that occurred during the drilling operation.

Drilling, Main Pillar of Oil/Gas Recovery

Official data shows that Iran’s recoverable hydrocarbon reserves have reached 160.12 billion barrels. A total of 390 oil and gas reservoirs have been identified across the country, 258 of which are oil reservoirs and the remaining 132 contain gas. Of them, 171 reservoirs have already been developed while 209 remain undeveloped. Among oil reserves, 141 (45%) have been developed and among gas reserves, 30 (70%) have been developed. These figures show that drilling is the key industry for the persistence and enhancement of production.

The drilling industry is one of the pillars and perhaps the main pillar of exploration of and production from hydrocarbon reservoirs, and the realization of the country's oil and gas production goals will not be possible without planning to organize and develop this industry. In other words, drilling is a specialized and capital-intensive industry that is done for exploration, development, description,maintenace, injection and operation of oil and gas reservoirs. The total number of Iranian drilling rigs operating in the onshore sector is more than 160, about 60% of which is owned by NIDC and the rest by private domestic and foreign companies. In the offshore sector, 62% of the rigs are owned by Iran and the rest are leased by domestic companies.

In recent years, leadinginternational drilling companies such as Schlumberger, Baker Hughes, and Halliburton have quitted their activities in Iran, thereby offering no services to Iran’s oil sector. However, Iranians involved in the drilling industry have been able to do well. The Iranian drilling industry is in a good position in terms of manpower and somehow has access to modern knowledge.

There are currently about 1,000 offshore oil and gas wells, some of which are over 25 years old. It is natural that these wells need constant maintenance. Currently, a significant portion of these wells operate at less than 50 percent efficiency and in some oil fields up to about 20 percent. At the same time, according to National Iranian Oil Company (NIOC) development strategies, hundreds of new wells need to be drilled in order to maintain and upgrade the current production ceiling.

Self-Reliance in Drilling Rigs

Oil and gas productionfrom deep reservoirs requires equipment, machinery and technical and engineering knowhow, among which, drilling oil and gas wells is one of the most complex and at the same time the most important elements.

Although satellite studies and other advanced facilities and equipment are used in the field of underground resource exploration today, the drilling rigs continue to maintain their top position. Iran recently managed to manufacture a drilling rig which is installed about 150 feet above the ground. It can support one million pounds of weight. It is fitted with a 500-tonne top drive, a rotary table and three 1,600-horsepower mud pumps. This rig has so far helped drill 15 wells measuring 51,000 meters in depth. The manufacturing of 700,000 items of widely used parts in the drilling industry in the past two decades has pushed scientific and research centers and local manufacturers and industrialists to consider full construction of an offshore drilling rig in Iran.

Local manufacturers are not able to supply drilling structure and infrastructure 100% for a drilling rig. In terms of drilling machinery, 70% is guaranteed by local manufacturing companies. Mud mixer, shale shaker, top drive, drilling fluid tank, water tank, butterfly valve and rotary valve have already been manufactured while drawworks and drilling mud are under construction. 

The technology for drawworks manufacturing was until recently monopolized by a limited number of industrialized nations, but now MashinSazi Arak is building drawworks. A drawwork is the primary hoisting machinery component of a rotary drilling rig. Its main function is to provide a means of raising and lowering the traveling block. The wire-rope drill line winds on the drawworks drum and over the crown block to the traveling block, allowing the drill string to be moved up and down as the drum turns.

The drilling fluid pump is also under construction by researchers at the Science Park of the University of Tehran, which is now 90% complete.

Mud pumps serve as the heart of the mud circulating system. Reciprocating piston pumps (also called slush pumps or power pumps) are widely used for drilling oil and gas wells. The advantages of the reciprocating positive-displacement pump include the ability to move high-solids-content fluids laden with abrasives, the ability to pump large particles, ease of operation and maintenance, reliability, and the ability to operate over a wide range of pressures and flow rates by changing the diameters of the compression cylinders (pump liners) and pistons.

Mud pumps come in a variety of sizes and configurations but for the typical petroleum drilling rig, the triplex (three piston/plunger) mud pump is used. Duplex mud pumps (two piston/plungers) have generally been replaced by the triplex pump, but are still common in developing countries. Two later developments are the hex pump with six vertical pistons/plungers, and various quintuplexes with five horizontal piston/plungers. The advantages that these new pumps have over convention triplex pumps is a lower mud noise which assists with better measurement while drilling (MWD) and logging while drilling (LWD) decoding.

Iran holds 157 billion barrels of recoverable oil and 34 tcm of recoverable gas reserves. Based on what was explained here, it is necessary and highly important to inject funds into the petroleum industry, particularly the costly drilling industry, for the development of hydrocarbon reservoirs and achieving maximum efficiency rate.

Courtesy of Iran Petroleum