Modelling and Simulation of Leakage-induced Pressure Drops Along Oil and Gas Pipelines
CHAPTER ONE
OBJECTIVES OF THEPROJECT
- To simulate a pipeline (using matlab) showing when the pipe is working at full capacity and when there is leak using the panhandle B equation for natural gases(methane). Any of the leak detection system mounted at such length of a pipe can detect
- To simulate a pipeline (using matlab) showing when the pipe is working at full capacity and when there is leak using the darcy weisbach equation for liquid products(gasoline). Any of the leak detection system mounted at such length of a pipe can detect
CHAPTER TWO
LITERATURE REVIEW
OIL EXPLORATION ANDPRODUCTION
The petroleum industry in Nigeria, is the largest industry and main generator of GDP in the continent’s most populous nation. Since the discovery of oil in the Niger Delta in the late 1950s. Developers in the pursuit of commercially available oil struck it big in 1956. Prior to the discovery of oil, Nigeria like many other African states strongly relied on agricultural exports to other countries to supply their economy. In fact, that’s what many Nigerians thought the developers were looking for—palm oil. But after nearly 50 years of searching for oil in the state, Shell-BP discovered the oil at Oloibiri in the Niger Delta. Wishing to utilize this new found oil opportunity, the first oil field began production in 1958.
As of 2000, oil and gas exports accounted for more than 98% of export earnings and about 83% of federal government revenue, as well as generating more than 14% of its GDP. It also provides 95% of foreign exchange earnings, and about 65% of government budgetary revenues.
Nigeria’s proven oil reserves are estimated at between 16 and 22 billion barrels (3.5×109 m3),. But other sources claim there could be as much as 35.3 billion barrels (5.61×109 m3). Its reserves make Nigeria the tenth most petroleum-rich nation, and by far the most affluent in Africa. In mid-2001, its crude oil production was averaging around 2.2 million barrels (350,000 m³) per day.
Nearly all of the country’s primary reserves are concentrated in and around the delta of the Niger River, but off-shore rigs are also prominent in the well-endowed coastal region. Nigeria is one of the few major oil-producing nations still capable of increasing its oil output. Unlike most of the other OPEC countries, Nigeria is not projected to exceed peak production until at least 2009. The reason for Nigeria’s relative unproductivity is primarily OPEC regulations on production to regulate prices on the international market. More recently, production has been disrupted intermittently by the protests of the Niger Delta’s inhabitants, who feel they are being exploited. Nigeria has a total of 159 oil fields and 1481 wells in operation according to the Ministry of
Petroleum Resources. The most productive region of the nation is the coastal Niger Delta Basin in the Niger Delta or “South-south” region which encompasses 78 of the 159 oil fields. Most of Nigeria’s oil fields are small and scattered, and as of 1990, these small unproductive fields accounted for 62.1% of all Nigerian production. This contrasts with the sixteen largest fields which produced 37.9% of Nigeria’s petroleum at that time. As a result of the numerous small fields, an extensive and well-developed pipeline network has been engineered to transport the crude. Also due to the lack of highly productive fields, money from the jointly operated companies (with the federal government) ventures is constantly directed towards petroleum exploration and production.
There are six petroleum exportation terminals in the country. Shell owns two, while Mobil, Chevron, Texaco, and Agip own one each. Shell also owns the Forcados Terminal, which is capable of storing 13 million barrels (2,100,000 m3) of crude oil in conjunction with the nearby Bonny Terminal. Mobil operates primarily out of the Qua Iboe Terminal in Akwa Ibom State, while Chevron owns the Escravos Terminal located in Delta State and has a storage capacity of 3.6 million barrels (570,000 m3). Agip operates the Brass Terminal in Brass, a town 113 km southwest of Port Harcourt and has a storage capacity of 3,558,000 barrels (565,700 m3). Texaco operates the Pennington Terminal.
Oil companies in Africa investigate offshore production as an alternative area of production. Deepwater production mainly involves underwater drilling that exists 400 m or more below the surface of the water. By expanding to deep water drilling the possible sources for finding new oil reserves is expanded. Through the introduction of deep water drilling 50% more oil is extracted[20]. Angola and Nigeria are the largest oil producers in Africa. In Nigeria, the deepwater sector still has a large avenue to expand and develop. The amount of oil extracted from Nigeria is expected to expand from 15,000 bbl/d (2,400 m3/d) in 2003 to 1.27 Mbbl/d (202,000 m3/d) in 2010[21]. Deepwater drilling for oil is especially attractive to oil companies because the Nigerian government has very little share in these activities and it is more difficult for the government to regulate the offshore activities of the companies[20]. Also, the deepwater extraction plants are less disturbed by local militant attacks, seizures due to civil conflicts, and sabotage. These advancements offer more resources and alternatives to extract the oil from the Niger Delta, with hopefully less conflict than the operations on land.
CHAPTER THREE
RESEARCH METHODOLOGY
PIPELINE DESIGN,EQUATION ANDMODELLING
The simplest way to convey a fluid, in a contained system from Point A to Point B, is by means of a conduit or pipe below.
CHAPTER FOUR
DATA PRESENTATION AND ANALYSIS
RESULTS AND ANALYSIS Natural gas(methane)
The simulation results for the flow rates at different pipe length is as shown in 1 while the graph as shown in graph 4.1 below. Both shows that as the length of pipeline increases, the gas flow rate decreases. This is true practically since flow rate is inversely proportional to length.
Table: Gas flow rates at different pipeline lengths.
CHAPTER FIVE CONCLUSION AND RECOMMENDATION
CONCLUSION
- The natural gas used in this work is methane because it constitutes 95% of natural gas. However, any of ethane, propane and normal butane would have given similar
- The pipeline efficiency used is 85% because that is the value for old pipelines and from the Appendix A(b), page 96, most of the pipelines in Niger Delta Areas are
- The pipeline inside diameter D=1219mm=48inchs was used. This is because in Appendix A(a) , page 95, the most abundant pipe diameter in use in Nigeria is 838mm=33inch, followed by 1219mm=48 inches. D=1219mm is selected because the panhandle B equationNuses D =36 inches or above.
- The simulation results as shown in 1 and graph 4.2 support already existing theory. Hence as pipeline length increases, the flow rate decreases. Similarly, as leak diameter increases the flow rates decrease.
- The panhandle B equation was chosen against panhandle A because it is an improvement from
- Pipeline control engineers should not treat with levity any small change in flow parameters eg volume and mass flow rates, pressure changes etc. This is the major breakthrough in this work as shown in graph 4.3 and Graph 4. 6. It shows that if both pipe length is kept constant, and the inserted host length for oil bunkering increases, the flow rate improves. This is even more felt when the leak diameter increases. Thus, the control room engineers may think a small leak is occurring not knowing that people are using long and wide host or pipe to tap oil from the
- The oil used for the liquid pipeline is The results followed similar trend as gas only that the flow rates is more felt in gas than in liquid. The flowrates in liquid is in barrel per day while in gas, it is in millions cubic feet per day.
RECOMMENDATIONS
- Pipeline engineers should treat small variations in flow parameters with urgency instead of terming it small leak. It may be bunkering with long and wide
- The other gas flow equations, Panhandle A and Weymouth should be improved upon for the same analysis and their results compared with this to estimate their performance rating and efficiency.
- It is equally recommended that the other natural gases be simulated to know how gas flow rates vary with their relative molecular mass. This will enable pipeline engineers to predict the flow characteristics of other natural gases with high molecular
- Pipeline operating companies should embrace the use of communication systems such as the fiber optic cables and the supervisory control and data acquisition(SCADA) for monitoring and localizing leaks in pipeline especially in remote areas where inspection by land is practically impossible.
- The various equations used by civil, mechanical and chemical engineers for calculating frictional factor f for flow of liquids in pipes should be harmonized into a unanimous equation. This is because the Colebrook –White equation which is generally accepted for evaluating f is implicit and requires iteration while the moody diagram is atimes trial and error
REFERENCES
- http://www.ingaa.org/File.aspx?id=12282
- Environmental impacts of oil spills in Niger-Delta: Department of petroleumresources report,
- Niger Delta Human Development Report.”2006.p.76.Retrieved 19 june
- Shell International Petroleum Company,Development,in Nigeria(London :march1995)
- Quoted in Greenpeace International, Shell Shocked,11(Greenpeace2013).
- I:Niger River Basin: A Vision for Sustainable Development pp.1-131,The World Bank,2005.
- Baired “Oils Shame in Africa”Newsweeks 27, 26July,2010.
- Junger;Blood Oil .Vanity fair.com.Retrieved 2may 2007,fromhttp://www.vanity/afri.com/politics/features/2007/02/Junger 2007.
- Nigeria Mourns Pipeline Victims”.BBC News.27-12-2007,Retrieved16-05-2008.
- http://www.oilandgasinjurylawyers.com/Major-Pipeline-Explosions-Oil-Spills.shtml
- Relufa, oil spill at chad-cameroon pipelines offshore terminal,27 April,2010
- Hana:”Egyptian oil spill Befouls Red Sea Resorts”,24 June2010.
- API RP 1130: Computational Pipeline Monitoring for Liquids. 1stEdition,American petroleum institute,September,2007.
