Buzachi Neft amends initial plan after studying new reservoir data
Оригинальный текст опубликован на сайте «Upstream», 24 November 2023 7:30 GMT . Автор: Материал доступен по .
Privately held oil producer in Kazakhstan, Buzachi Neft, has had to allocate at least two additional months to establish full control over a damaged well in the Mangistau region that has been flaring escaping gas from the beginning of June after an onsite accident.
In an update of its efforts that was released on Thursday, Buzachi Neft acknowledged that its initial plan to halt the flow of gas via the wellbore of the #303 exploration well at the onshore Karaturun East field by pumping water into the formation has only reduced the outflow of gas, but not stopped it completely.
The operator drilled two injection holes into the formation at the depth of around 1200 metres and pumped around 40,000 tonnes of water underground between 13 October and 20 November, it said.
Additionally, Buzachi Neft conducted logging studies at one of the injection wells before putting it into operation, it added.
These studies have shown that gas flows into the incident well from two thin Jurassic formations, each with the thickness of not more than two metres, the operator said.
With better understanding of the formations from where the gas and water escape to the surface, Buzachi Neft has now amended the direction of a third well, 303-ST.
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This well was planned to approach and then penetrate the wellbore of the accident well at the depth of 460 metres.
However, Buzachi Neft said that under the amended plan, the drilling of 303-ST will be continued so that it would enter the wellbore of the incident well at a depth of more than 1000 metres.
Once this step is completed, the operator intends to start injecting heavy drilling mud and a cementing mixture via 303-ST into the wellbore of the incident well to completely halt the outflow of gas to the surface.
Drilling of the 303-ST well is nearing completion. The mud injection is planned to start not later than 1 December and will continue for about one month before the burning of gas at the well stops completely, Buzachi Neft said.
Earlier in November, Kazakh authorities revealed some shocking results of their investigation into the sequence of events that led to the blowout on well #303 during the lifting of the drill bit and subsequent fire that wiped out the drilling rig and formed a crater around the hole to complicate access to the site.
The incident attracted international attention in August after French environmental intelligence company Kayrros said that, based on interpretation of satellite images of the accident site, the well was emitting dozens of tonnes of methane each day.
Buzachi Neft denied the satellite findings and even resorted to over the burning well to demonstrate that almost all of the escaping methane was burning out, rather than venting into the atmosphere.