PIPE LINE EXPLOSION: A NEW LOOK BASED ON THEORY

Perhaps the most publicized industrial accidents of recent times occurred at the nuclear reactors at Chernobyl, Three miles island, , Macondo well in the Gulf of Mexico and Oil spills in Niger Delta. They and numerous other less noted accidents share common theme. They involve accidental explosions in industrial piping systems not all the cases of pipe vandalism.

Numerous industrial explosions share several common factors: fluid transients were known to occur; trapped flammable gases were known to collect in the piping system; fluid transient sometimes cause pressures exceeding 1000psi which meet the required pressures for auto ignition of gases and explosion in piping occurred with causes that are not yet well understood.

A theory developed by Robert A. Leishear a fellow engineer and member of ASME that many explosions. The theory states that if piping contains a flammable gas and there is an inrush of fluid (or fluid transient) in to the piping, the gas can adiabatically compress to its auto ignition point( similar to a diesel engine) and then the gas, given sufficient quantity and pressure, can ignite and explode. Although further researches are required to support the theory, the safety and environment implications of this theory are significant.

Consider the accident summaries for Chernobyl, Three Mile Island and Fukushima Daiichi cite the presence of fluid transients’ plus flammable hydrogen and oxygen in the piping systems. Each of these accidents was caused by events other than explosions, but explosions were reported following accidents onsets.

At Fukushima Daiichi, loss or of reactor coolant followed flooding due to an earthquake induced tsunami. According to this theory, hydrogen and oxygen were generated in the piping through the radioactive decomposition of coolant water. A subsequent inrush of sea water used to cool the reactors could have provided conditions required to cause explosions.

How might the accident at the Macondo Well be related to explosions in nuclear reactor piping or even and oil spill? An explosion at an oil rig was accompanied by shearing of the piping near the sea floor. The new theory may provide a relationship between these seemingly disparate explosions. Flaming gases are known to contribute to fires and explosions in oil pipelines. “Swiss, run, boom” is a common refrain reported by operators describing fires and explosion on offshore rigs. If upward –traveling gas collects between two separate slugs of liquid during the transfer of oil up through a pipeline, conditions may exist to ignite the gas. One slug of liquid can lose momentum and slow down if a large gas pocket is present. The other slug of liquid may accelerate and compress the trapped gas. Depending on the volume of the gas flow rates of the two liquid slugs, auto ignition conditions may exist.

“Swish” would be the sound that would be heard if the gas in the pipeline explodes and accelerates one of the oil slugs in the pipeline up towards the drilling rig. One would have time to “run” before the “boom” occurs, which may damage undersea piping as well as the oil rig. That is the conditions to initiate observed explosions and fire was potentially present during past explosions in pipe lines.

Overall there exist certain similarities between these different explosions to be coincidence. Spills in populated areas often spread out over a wide area, destroying crops and aquaculture through contamination of the ground water and soils. People in the affected areas complain about health issues including breathing problems and skin lesions; many have lost basic human rights such as health, access to food, clean water, and an ability to work which in a way is similar to the other accidental areas although not with mutation issues.

Oil spills are a common event in Nigeria and occur due to a number of causes, including: corrosion of pipelines and tankers (accounting for 50% of all spills), sabotage (28%), and oil production operations (21%), with 1% of the spills being accounted for by inadequate or non-functional production equipment. The largest contributor to the oil spill total, corrosion of pipes and tanks, is the rupturing or leaking of production infrastructures that are described as, "very old and lack regular inspection and maintenance". A reason that corrosion accounts for such a high percentage of all spills is that as a result of the small size of the oilfields in the Niger Delta, there is an extensive network of pipelines between the fields, as well as numerous small networks of flow-lines—the narrow diameter pipes that carry oil from wellheads to flow-stations—allowing many opportunities for leaks. In onshore areas most pipelines and flow-lines are laid above ground.
 Pipelines, which have an estimate life span of about fifteen years, are old and susceptible to corrosion. Many of the pipelines are as old as twenty to twenty-five years. Most of the facilities were constructed between the 1960s and early 1980s to the then prevailing standards. SPDC [Shell Petroleum and Development Company] would not build them that way today.” Sabotage is performed primarily through what is known as "bunkering", whereby the saboteur attempts to tap the pipeline. In the process of extraction sometimes the pipeline is damaged or destroyed. Oil extracted in this manner can often be sold.
Sabotage and theft through oil siphoning has become a major issue in the Niger River Delta states as well, contributing to further environmental degradation.  Damaged lines may go unnoticed for days, and repair of the damaged pipes takes even longer. Oil siphoning has become a big business, with the stolen oil quickly making its way onto the black market . While the popularity of selling stolen oil increases, the numbers of deaths are increasing. In late December 2006 more than 200 people were killed in the Lagos region of Nigeria in an oil line explosion.

This new theory is based on the fundamental physics of fluid and gas dynamics and its consistent with explosions. Ordinarily, it is logical when pipe lines are vandalized however, with certain conditions it could be seen theoretically that fluid pressure in pipe could bring about certain burst causing oil spills and explosion.