Tashkent, Uzbekistan (UzDaily.com) — A hydrogen sulfide leak has been officially confirmed at the “25 Years of Independence” (M-25) field, located in the “Kofrun” mahalla of Baysun District, Surkhandarya Region.

Today, a briefing was held in the “Kulkamish” mahalla of Baysun District regarding the technological incident at the “25 Years of Independence” field. The event was attended by Energy Minister Jurabek Mirzamakhmudov and Minister of Emergency Situations Major General Abdulla Kuldoshev.

It was reported at the briefing that the day before, around 4:00 PM, a hydrogen sulfide leak under high pressure was detected from the side of well No. 604 at the “25 Years of Independence” (M-25) field.

As a result of the accident, 4 people were killed, and 11 others were injured and hospitalized. On the same day, 10 of the injured were discharged from the hospital. The families of the deceased have been placed under care, and ERIELL Group will provide compensation.

Company advisor Azizbek Nazarov noted: “The company will also take responsibility for supporting the children of these families and will cover their future higher education expenses.”

It should be noted that on September 1, at 3:17 PM, a hydrogen sulfide leak occurred at well No. 604 of the M-25 field due to a breach of technological processes during drilling. To address the aftermath of the incident, an operational headquarters was established with the participation of representatives from national-level ministries and agencies. Under their supervision, on September 15, the well was sealed, and the gas leak was fully eliminated.

Currently, specialists continue necessary work at the site of the incident.

Responding to a question about the reasons for the repeated incident, Energy Minister Jurabek Mirzamakhmudov explained that it is related to the geographical location of the field and its specific characteristics.

The “25 Years of Independence” field is located in Surkhandarya Region, 20 kilometers southeast of the city of Baysun. Geographically, the area is a foothill hilly zone with an elevation of 1,000 meters above sea level.

The M-25 (Gajak) field was first discovered in 1933 during geological surveys and was prepared for development in 1938. The first exploratory well was drilled in 1941. In 1974, during tests of well No. 5, industrial gas reserves were obtained from Lower Cretaceous deposits, and the structure was classified as a field.

The initial reserves of the field were estimated at 40 billion m³. In 2006-2008, Malaysian company PETRONAS, in collaboration with Uzbekneftegaz, conducted 3D seismic surveys at the Gajak field and tested one well.

Direct investments amounted to USD 102 million, but the company exited the project due to the complexity of field development and changes in its investment policy.

The M-25 field is characterized by complex geological and technical conditions. Its geological structure includes numerous structural disruptions and a variety of filtration and reservoir properties, which require cluster drilling to depths of up to 1,200 meters.

The gas reserves are classified as hard-to-recover. The initial proven reserves are 108.6 billion m³, with an expected recoverable gas volume over a 30-year production period of 1.2 billion m³, with a recovery factor of 0.77.

The natural gas from this field contains high concentrations of hydrogen sulfide (up to 7%) and carbon dioxide (up to 12%).

Reservoir pressure reaches 65 MPa, and the subsurface temperature can reach 150°C.