The World’s Biggest Oil Companies

Different criterions give you different rankings of the oil companies. Usually in this industry, the production and the reserve are the most useful factors to assess the companies. It is really difficult to tell the reserve a state-owned oil company have, usually which is regarded as top secret, sometimes even the oil company publicized its reserve but the figure was still not convincing1. In this following 2012 ranking of the world’s biggest is based on the combined volumes of oil and natural gas that these companies produce each day, which allows the comparison of private sector and state-owned oil companies.2, 3.


1. 2012 working interest production volumes calculated by Wood Mackenzie reflects oil plus the energy equivalent in natural gas2.

2. The unit of working interest production volumes is million barrels per day(mbpd).

3. The owners were listed in the parenthesis if a company is state-owned or a public company controlled by the government.

4. The Wikipedia pages of the companies have been hyperlinked.

Saudi Aramco(Saudi Arabia) 12.5 mbpd

Gazprom(Russia) 9.7 Mbps

National Iranian Oil Co.(Iran) 6.4 mbpd

ExxonMobil 5.3 mbpd

PetroChina 4.4 mbpd

BP 4.1 mbpd

Royal Dutch Shell 3.9 mbpd

Pemex(Mexico) 3.6 mbpd

Chevron 3.5 Mbps

Kuwait Petroleum Company 3.2 mbpd

Abu Dhabi National Oil Company(the United Arab Emirates) 2.9 mbpd

Sonatrach(Algeria) 2.7 mbpd

Total 2.7 mbpd

Petrobras(Brazil) 2.6 mbpd

Rosneft(Russia) 2.6 mbpd

Iraqi Oil Ministry(Iraq) 2.3 mbpd

Qatar Petroleum(Qatar) 2.3 mbpd

Lukoil 2.2 mbpd

Eni 2.2 mbpd

Statoil 2.1 mbpd

ConocoPhillips 2.0 mbpd

Petroleos de Venezuela(Venezuela) 1.9 mbpd

Sinopec 1.6 mbpd

Nigerian National Petroleum Company 1.4 mbpd

Petronas(Malaysia) 1.4 mbpd


1. WikiLeaks cables: Saudi Arabia cannot pump enough oil to keep a lid on prices.

2. The World’s 25 Biggest Oil Companies.

3. Petroleum Intelligence Weekly Ranks World’s Top 50 Oil Companies.


Mature Field

Today I am going to talk about mature field, which is not a new but development concept. The definition of this term varies with personnels. In Dr.Tayfun Babadagli’s review paper, Development of Mature Field-A Review, he defined three times. 1. The oil fields after a certain production period, which is very ambiguous; 2. The fields have reached the peak of their production or those producing fields in declining mode; 3. The fields have reached their economic limit after  primary and secondary recovery efforts1. Fig.1 shows the second definition of mature field, which was recommended by Halliburton. If the Mature Field in the typical production life of a field graph was replaced by Peak Production, after reaching Economic Limit the oilfield was regarded as mature field, that is the third definition Dr. Tayfun has given.

Fig. 1 Typical Production Life of a Field2.

Also, we have to talk about new fields and old fields here. Sometimes, mature field means old field. The two definitions are similar but not exactly the same. To simplify the problem here, most mature fields are old, but old fields may not be mature. Why? The economic limit is dynamic, due to the developments of technology, the production cost and the oil price.

As we know, during the primary recovery, reservoir drive comes from natural mechanisms3. Once the reservoir pressure is not high enough to drive the oil to the ground, external energy are needed to provide the drive to push or pull the oil from underground, such as water flooding, pumps, gas lift, or natural gas injection3. All the techniques for increasing the amount of crude oil that can be extracted from an oil field other than primary and secondary recovery methods could be tertiary recovery methods, also named enhanced oil recovery(EOR) or improved oil recovery(IOR)4. Among those three names, EOR is the most popular. Also, traditionally EOR is not equal to IOR, just as Drs. Don W Green and G. Paul Willhite said in their SPE textbook, Enhanced Oil Recovery, IOR includes EOR but also encompasses a broader range of activities, e.g., reservoir characterization, improved reservoir management(characterize, monitor, and manage the producing reservoir), and improved drilling and completions5, 6. To revitalize the mature fields, IOR methods should be applied.

In Joel Parshell, the Journal of Petroleum Technology(JPT) feature editor’s article, Mature Fields Hold Big Expansion Opportunity, in the Oct 2012 issue of Society of Petroleum Engineers’ flag magazine JPT, he reviewed the advancement of new techniques and development strategies for the mature fields6. Also, the articles about EOR and completions in the same issue are recommended.

1. Development of Mature Field-A Review.

2. What is a Mature Field?

3. Extraction of Petroleum.

4. Enhanced Oil Recovery.

5. Green, D.W., and Willhite, G.P., Enhanced Oil Recovery, Textbook Series, SPE, Richardson, TX (1998) 1.

6. Mature Fields Hold Big Expansion Opportunity.

Shale Gas

When we talk about shale gas, we need to know what is shale gas. Simply speaking, shale gas refers to the natural gas produced from shale, sedimentary rocks of laminated structure formed by the deposition of successive layers of clay1, 2. The shale looks like the pages of a book, very thin (formed by compaction) and brittle (due to its composition of clay). Also the porosity and permeability of shale rocks are very low, which make it difficult and uneconomical to produce natural gas locked in tight, impermeable shale1. Thus, shale gas is regarded as unconventional gas resources which also include tight gas, coal-bed methane, and gas hydrates3. With the advancement of horizontal well drilling and hydraulic fracturing technologies, production of shale gas became technically and economically possible, even a hot topic in oil and gas industry, especially in United States4. Mr. Fred Julander, the president of Julander Energy, said that shale gas was the most important energy development since the discovery of oil5. Major gas shale basins exist throughout the lower-48 United States. There are at least 21 shale basins in more than 20 states6.

Fig. 1 Major US Shale Basins7

The Barnett Shale play is reportedly the most active natural gas play in the United States with as many as 182 drilling rigs at work in 20086, 8. According to the Railroad Commission of Texas’s statistic data, as of September 22, 2010, there are total of gas wells 14401 entered on RRC recrods since the discovery of Newark, East (Barnett Shale) Field on October 15, 19819. For January through July 2010, gas well gas production accumulated for 1025 Bcf, which accounts for 27% of Texas production9. Total natural gas production in North Texas’ Barnett Shale has passed a milestone level of 8 TCF10. Until January 1, 2009, as the biggest Barnett Shale producer, XTO Energy Inc.’s Well TRWD #H 2H in Tarrant County has produced 4.4 Bcf gas in 43 months11. While EOG Resources, Inc.’s Well Fowler $4H in Johnson County had a record of 8.6 MMCFGPD peak month as the biggest Barnett Shale well based on peak month daily average11. There are a total of 234 operators in the Newark, East (Barnett Shale) Field now9. In 2002, Devon Energy Production Co., L.P. Purchased Mitchell Energy & Development for $3.5 billion in cash and stock from Mr. George Mitchell, the father of the Barnett Shale, and has established itself as the leading producer from the Barnett Shale9, 12. Not only the advancement of technologies, but also the increased price and gas demand drove the development of shale gas. In another hand, the development of shale gas lower the price of natural gas13.

Now water issue has become the biggest problem despite of the economic downturn and resulting lower natural gas prices14. Hydraulic fracturing needs tremendous water to crack the formation thousands of feet under the ground, especially in the water lack area, such as Texas. For a typical horizontal well frac, it needs more than 3 million gallons water14. The potential pollution from the chemicals in the hydraulic fracturing fluids may halt the application of this technology15.

Fig. 2. Horizontal Well Drilling and Hydraulic Fracturing16


1. US Shale Gas Brief.

2. Shale.

3. International Energy Agency, World Energy Outlook 2010, Chapter 5 , Natural gas market outlook, Page 187.

4. Shale Gas.

5. Kuuskraa, V.A., et al., Worldwide Gas Shales and Unconventional Gas: A Status Report.

6. Andrews, A., et al., Unconventional Gas Shales, Development, Technology, and Policy Issues.

7. What You Need To Know About Shale Gas Investing and the Pros and Cons of Fracking.

8. RigData Rig Stats.

9. Newark, East (Barnett Shale) Statistics Updated: 09/23/10.

10. Barnett Shale natural gas field passes a milestone.

11. Powell, Jr., M.E., Recent Developments in the Barnett Shale.

12. The Father of Shale Gas.

13. As Oil Explodes, Why Natural Gas Prices Stay Low.

14. Texas Energy Sector & Barnett Shale Update.

15. Barnett Shale.

16. The Marcellus Shale: New York is the Natural Gas Industry’s New Lab Rat.

Traffic Jams, Automobiles, Oil and Gas, and Alternative Energy

Recently, the traffic jams in Beijing trouble the capital of People’s Republic of China, with intensity1. I had the experience of traffic jams in Beijing. Under such kind of dituations, the highways seemed to be a huge parking lot. Now people, including me, call Beijing as Top Jams (pronounced as shou 3 du 3 in Chinese) instead of capital (pronounced as shou 3 du 1). The traffic jams happened intenser and more frequently due to the increasing private cars, especially in the severe weather and holiday seasons2, 3. The monster traffic jam in mid-August make the capital seem to be a huge parking lot4, 5. Shai Oster stated that Beijing considers car limits to fight for the traffic jams in his blog6, actually the policy has been implemented for years. Starting in 2008, Beijing authorities started to limit the cars on road through having the drivers leave theirs at home once a week based on the last digit of the license plate6.. The problem is that some of the owner could buy the second car to avoid the limitation. That is not the only tradition Chinese have. Above I mentioned that the holiday seasons made the traffic jams worse. Each year, Chunyun (transportation in Spring Festivals) could move more than 2 billion people times7. This year, Beijing fell into its most severe traffic jam around mid-Autumn festival season3. According to Beijing Municipal Traffic Committee, the Beijing municipal government would invest 80 billion RMB in 2009 on transportation infrastructure construction to solve the traffic problems8. Obviously the construction has not solved the problem, yet. Actually, in my opinion, simply increasing the investment in transportation construction will never work, especially with the current urban planning and increasing cars.

The increases of private cars also push up the oil price. According to International Energy Agency outlook, the oil peak will not reach until 2035, and drives the oil price over $200 per barrel by 2035, equivalent to $113 in 2009 real dollars9. The demand by China is projected to account for 39% of rising energy demand and 57% of rising oil demand9. Kevin Clarke said that China does not have to take any lessons from America on consumption because the planet could not support the 1.3 billion people have the same standard living level as current Americans have10.The attitude is so negative that I could not agree with at all. We could not wait the day after tomorrow coming without any efforts. The alternative energy resources could solve the problem? I am highly doubting it. In fact I have some advices on how to deal with such a situation.

  1. Developing the public transportation with alternative energy resources.
  2. Limiting the private cars, especially with fossil fuel.
  3. Increasing the consumption tax on oil and gas.
  4. Lowering the gap between conventional and alternative energy prices.
  5. Improving the technology and energy efficiency
  6. Reducing the energy consumption.


  1. Beijing traffic jams only growing.
  2. Beijing roads choked by 140 traffic jams in a day.
  3. Traffic Jams In Beijing Reach New Records Of Congestion.
  4. Beijing: World’s Biggest Parking Lot.
  5. China Traffic Jam Could Last Weeks.
  6. Beijing, Fighting Traffic, Considers Car Limits.
  7. Chunyun.
  8. Beiijng strives to solve traffic problems.
  9. International Energy Agency says ‘peak oil’ has hit. Crisis averted?
  10. Take the next exit: Avoid an economic traffic jam.

Applied Microbiology and Molecular Biology in Oilfield Systems

The first and second International Symposium on Applied Microbiology and Molecular Biology in Oil Systems were held in Colchester, United Kingdom from September 17-18, 2007 and Aarhus, Denmark from June 17-19, 2009, respectively. The next symposium will be held in Calgary, Alberta from June 13-15, 2011.

The first symposium was co-organized by University of Exxex and Danish Technological Institute, and the details about it could be found at International Symposium on Applied Molecular Microbiology in Oil Systems (ISMOS), especially the slides presented at the conference.

The second symposium was mainly held by the Danish Technological Institute, and the details could be found at its website, since it is temporarily not available now. Once I can access it, I will update the information here as soon as possible. Fortunately, the proceedings of the symposium has been published as Applied Microbiology and Molecular Biology in Oilfield Systems. The book was divided into five parts: 1 Introduction, Sampling and Procedures; 2 Application of Molecular Microbiological Methodsto the Oil Industry; 3 Problems Caused by Microbes to the Oil Industryand Treatment Strategies; 4 How Specific Microbial Communities Benefit the Oil Industry; 5 Fuel for the Future. The author started the book from the most probable number(MPN) technique, which is the traditional and fundamental method to count the number of microbes in media. In the second part several papers introduced the application of molecular microbiological methods to the oil industry, such as qualitative (which microbial communities are presented) and quantitative (how many microorganisms are present)analysis of microbes in the oil reservoirs. The problems (bio-corrosions and bio-fouling) caused by microbes and treatment technologies were presented in the third part. The benefits of microbes to the oil industry (upgrading the oil in processing and MEOR in E&P) were described in the following part. Finally, the applications of microbes in biofuels also were mentioned. A brief description of each method used by some of the contributing authors in this book was also attached.

The information for the next symposium could be reached at its official website. I am glad to see more progress of applied microbiology and molecular biology in oilfield.

Scientists Found Oil on the Gulf of Mexico Floor

Two months ago, I discussed two inconsistent articles about the destiny of oil plume from Well Macondo 242 in the Gulf of Mexico which were published on Science Express. In the post, I listed the ideas of the parties and did not support anyone of them. The White House claimed that the oil had gone by several oil-spill clean technologies, including the breakdown of the bacteria. Researchers from Lawrence Berkeley National Laboratory and University of Oklahoma confirmed that later. Shortly before the confirmation, the results of Woods Hole Oceanographic Institution failed the claim. I suspected the claim because of the quick degradation rate by the bacteria in such an environment without enough oxygen.

The latest news make people tend to believe that the oil is still in the ocean. Yesterday, it is reported that scientists found a large amount of oil accumulated at the bottom of the Gulf of Mexico. The research ship Cape Hatteras found the oil in samples dug up from the seafloor in a 140-mile around the Deepwater Horizon well site1,2. It is highly possible that the oil came out from the Well Macondo 242.  While, oil spill environmental forensic tests are needed to fingerprint the oil, identify its source, and verify the hypothesis1~3.


1. Research teams find oil on bottom of Gulf.

2. Scientists find lots of oil on gulf floor.

3. Oil Spill Environmental Forensics: Fingerprinting and Source Identification.

Modern Chemical Enhanced Oil Recovery, Theory and Practice

Yesterday, before I wrote the previous blog, I occasionally found a new book, Modern Chemical Enhanced Oil Recovery, Theory and Practice by James J. Sheng. That is the latest book about enhanced oil recovery I have ever known. I am not familiar with the author. I cannot find an introduction to him within the book. Thus, I searched his publications within, which collects all the papers published on Society of Petroleum Engineers (SPE) journals or presented at SPE conferences. The system returned to 10 results, including 3 journal publications and 7 conference papers. To my lucky, I found a brief introduction to his education background and working experience. After having received his B.S. from University of Petroleum, China, Dr. Sheng pursued his M.S. and PhD. degree in petroleum engineering at University of Alberta. All the papers but one he published was his work with Baker Hughes, an oil service company headquartered at Houston, TX, where he worked as a research scientist. Now he is working with Total as a senior research engineer at Houston, TX. He published the last paper SPE 102659 on SPE Reservoir Evaluation & Engineering in Jun., 2008. Within the acknowledgement of the new book, he expressed his thanks to professors from University of Texas at Austin and personnels from Total mainly. It is possible that Dr. Sheng has joint projects with the UT. I do not have a chance to study the book, yet; since I believe a two years’ efforts with more than 15 years experience in this area could turn out a practical manual with theoretical explanations to chemical EOR technologies for petroleum professionals, especially for those who are working in enhanced oil recovery. One more thing, I am glad to see that he did not put microbial enhanced oil recovery in this book. Maybe he has the similar idea as me that MEOR is independent, instead of one of the chemical EOR technologies. The table of context of this book is listed below:

Chapter 1 Introduction;

Chapter 2 Transport of Chemicals and Fractional Flow Analysis;

Chapter 3 Salinity Effect and Ion Exchange;

Chapter 4 Mobility Control Requirement in EOR Processes;

Chapter 5 Polymer Flooding;

Chapter 6 Polymer Viscoelastic Behavior and Its Effect on Field Facilities and Operations;

Chapter 7 Surfactant Flooding;

Chapter 8 Optimum Phase Type and Optimum Salinity Profile in Surfactant Flooding;

Chapter 9 Surfactant-Polymer Flooding;

Chapter 10 Alkaline Flooding;

Chapter 11 Alkaline-Polymer Flooding;

Chapter 12 Alkaline-Surfactant Flooding;

Chapter 13 Alkaline-Surfactant-Polymer Flooding.