Sidoarjo mud flow
A magnitude 6.3 earthquake occurred in Yogyakarta at ~06:00 local time 27 May 2006, approximately 250 kilometres Southwest of Sidoarjo. Seven minutes after the earthquake a mud loss problem in the well was noted. After two major aftershocks, the well suffered a complete loss of circulation. A loss of circulation happens when drilling mudâ€"necessary for maintenance of wellbore stabilityâ€"that is pumped down a shaft does not return to the surface but is lost into some opening or a fault system. This mud loss problem was finally stopped when loss circulation material was pumped into the well, a standard practice in drilling an oil and gas well. A day later the well suffered a ‘kick’, an influx of formation fluid into the well bore. The kick appears to have been killed within three hours. The next day, on 29 May 2006, steam, water and mud began erupting up to 200 meters above the well, a phenomenon that is now known as the Lusi mud volcano.The birth of Lusi was a major disaster for the population living nearby, with loss of their houses, properties and their livelihood. For the scientific community, however, it was a chance to study the evolving geological process of a mud volcano. In the past, mud vulcanologists could only study existing or ancient mud volcanoes during dormant periods. Thus, Lusi is a rare occasion and a unique opportunity to conduct scientific experiments to further our understanding. It also offers opportunities to study the down hole condition of a mud volcano from the neighboring Banjar-Panji exploration well lithologies.
The relatively close timing of the Yogyakarta earthquake, the problems of mud loss and kick in the well and the birth of the mud volcano continue to interest geoscientists. Was the mud volcano due to the same seismic event that triggered the earthquake? Geoscientists from Norway, Russia, France and Indonesia have suggested that a major fault nearby may have been reactivated, creating a mud flow path that caused Lusi.
They have identified more than 10 naturally triggered mud volcanoes in the East Java province, with at least five near the Watukosek fault system, confirming that the region is prone to mud volcanism. They also showed that surface cracks surrounding Lusi predominantly run NE-SW, the direction of the Watukosek fault. Increased seep activity in the mud volcanoes along the Watukosek fault coincided with the May 27, 2006 seismic event. A major fault system may have been reactivated, resulting in the formation of a mud volcano.
In June 2008, a report released by British, American, Indonesian, and Australian scientists, concluded that the volcano wasn't a natural disaster, but the result of oil and gas drilling.
On June 5, 2006, MedcoEnergi sent a letter to PT Lapindo Brantas which accused them of breaching safety procedures during the drilling process. The letter further attributes "gross negligence" to the operator company for not equipping the well bore with steel safety encasing. Soon afterwards then-vice president Jusuf Kalla announced that PT Lapindo Brantas and the owner, the Bakrie Group, would have to compensate thousands of victims affected by the mud flows. Criminal investigations were then initiated against several senior executives of the company because the drilling operation had put the lives of local people at risk.
On August 15, 2006, the East Java police seized the Banjar-Panji 1 well to secure it for the court case. The Indonesian environmental watchdog, WALHI, meanwhile had filed a lawsuit against PT Lapindo Brantas, President Susilo Bambang Yudhoyono, the Indonesian Minister of Energy, the Indonesian Minister of Environmental Affairs and local officials.
After investigations by independent experts, police had concluded the mud flow was an "underground blow out", triggered by the drilling activity. It is further noted that steel encasing lining had not been used which could have prevented the disaster. Thirteen Lapindo Brantas' executives and engineers face twelve charges of violating Indonesian laws.
As of October 30, 2008, the mud flow was still ongoing at a rate of 100,000 m3 per day. By mid August 2011, mud was being discharged at a rate of 10,000 m3 per day, with 15 bubbles around its gushing point.
A study by a group of Indonesian geo-scientists led by Bambang Istadi predicted the area affected by the mudflow over a ten-year period. The model simulated the mud flow and its likely outcome in order to find safe locations to relocate people and affected infrastructures.
After new hot gas flows began to appear, workers started relocating families and some were injured in the process. The workers were taken to a local hospital to undergo treatment for severe burns. In Siring Barat, 319 more families have been displaced and in Kelurahan Jatirejo, 262 new families are also going to be affected by the new flows of gas. Protesting families took to the streets demanding compensations, which in turn added more delays to the already stressed detour road for Jalan Raya Porong and the The Porong-Gempol toll road.
The government has stated that their heart was with the people, however the cabinet meeting on how to disburse compensation has been delayed until further notice. A local official Saiful Ilah signed a statement announcing that, "The government is going to defend the people of Siring." Following this announcement protests came to an end and traffic flow returned to normal an hour later.
New mudflows spots have begun in April 2010, this time on Porong Highway, which is the main road linking Surabaya with Probolinggo and islands to the east including Bali, despite roadway thickening and strengthening. A new highway is planned to replace this one however are held up by land acquisition issues. The main railway also runs by the area, which is in danger of explosions due to seepage of methane and ignition could come from something as simple as a tossed cigarette.
As of June 2009, the residents had received less than 20% of the suggested compensation. By mid-2010, reimbursement payments for victims have not been fully settled, and legal actions against the company have stalled. It is worth mentioning that the owner of the energy company, Aburizal Bakrie was the Coordinating Minister for People's Welfare at the time of the disaster, and is currently the chairman of one of the most influential political parties in Indonesia.
| In 2011, Lapindo independent Social Impact Report. | Brantas published an - |
Out of the three hypotheses on the cause of the Lusi mud volcano, the hydro fracturing hypothesis appeared to be the one most debated. On 23 October 2008 a public relations agency in London, acting for one of the oil well's owners, started to widely publicise what it described as "new facts" on the origin of the mud volcano, which were subsequently presented at an American Association of Petroleum Geologists conference in Cape Town, South Africa on 28 October 2008. The assertion of the geologists and drillers from Energi Mega Persada was that "At a recent Geological Society of London Conference, we provided authoritative new facts that make it absolutely clear that drilling could not have been the trigger of LUSI." Other verbal reports of the conference in question indicated that the assertion was by no means accepted uncritically, and that when the novel data is published, it is certain to be scrutinised closely.
In 2009, this well data was finally released and published in the Journal of Marine and Petroleum Geology for the scientific community uses by the geologists and drillers from Energi Mega Persada. It is a common practice in the oil and gas industry to closely guard their drilling and geologic information, and the company involved is of no exception. After such release, however, future scientific research on Lusi should have an access to a set of credible data and not as constraint as early authors were in their limited and questionable quality data to back their claims.
After hearing the arguments from both sides for the cause of the mud volcano at the American Association of Petroleum Geologists International Convention in Cape Town in October 2008, the vast majority of the conference session audience present (consisting of AAPG oil and gas professionals) voted in favor of the view that the Lusi (Sidoarjo) mudflow had been induced by drilling. On the basis of the arguments presented, 42 out of the 74 scientists came to the conclusion that drilling was entirely responsible, while 13 felt that a combination of drilling and earthquake activity was to blame. Only 3 thought that the earthquake was solely responsible, and 16 geoscientists believed that the evidence was inconclusive.
The report of the debate and its outcomes was published in AAPG Explorer Magazine. The article stated that the voting process was a decision by the moderator and only reflected opinions of a group of individuals in the session room at that time and in no way endorsed by the association. It further cautioned readers not to consider the voting result in any way as a scientific validation.
On the possible trigger of Lusi mud volcano, a group of geologists and drilling engineers from the oil company countered the hydro fracturing hypothesis. They suggested that analysis based on the well data showed that the well was safe and pressure in the well bore was below the critical pressure. It is therefore unlikely that the well was fractured as charged. Their paper also published data and well information for the 1st time to the scientific communities as opinions and technical papers up to that time lacked accurate well data and were forced to rely on a number of assumptions.
In February 2010, a group led by experts from Britain's Durham University said the new clues bolstered suspicions the catastrophe was caused by human error. In journal Marine and Petroleum Geology, Professor Richard Davies, of the Centre for Research into Earth Energy Systems, said that drillers, looking for gas nearby, had made a series of mistakes. They had overestimated the pressure the well could tolerate, and had not placed protective casing around a section of open well. Then, after failing to find any gas, they hauled the drill out while the hole was extremely unstable. By withdrawing the drill, they exposed the wellhole to a "kick" from pressurised water and gas from surrounding rock formations. The result was a volcano-like inflow that the drillers tried in vain to stop.
In the same Marine and Petroleum Geology journal, the group of geologists and drilling engineers refuted the allegation showing that the "kick" maximum pressure were too low to fracture the rock formation. The well pressure analysis based on credible data showed that the well is stronger than the maximum pressure exerted on the well. This implied that the hydro fracturing hypothesis is likely to be incorrect. They further stated that the model developed by Prof. Davies is much too simplistic by not considering all the available dataset and information in its analysis.
Related Sites for Sidoarjo mud flow
- Pictures: Deadly Mud Volcano to Erupt for 26 More Years read Sidoarjo mud flow
- 6 Natural Disasters That Were Caused by Human Stupidity | Cracked.com read Sidoarjo mud flow
