On June 23, it was learned from China National Petroleum Corporation (hereinafter referred to as “PetroChina”) that at 13:10, PetroChina completed the drilling of Well Shuangyu 001-H6 in the Southwest Oil and Gas Field to a depth of 9,010 meters, creating China’s The record for the deepest onshore gas well marks that PetroChina’s ultra-deep well drilling capability has reached a new level. This is another major breakthrough made by PetroChina in vigorously developing ultra-deep drilling technology based on high-level scientific and technological self-reliance.
Well Shuangyu 001-H6 is an ultra-deep, ultra-high temperature and ultra-high pressure horizontal well in Tianbali structure in Shuangyushi block. Drilling logs show that the well temperature exceeds 180 degrees Celsius, the formation pressure exceeds 130 MPa, and the hydrogen sulfide content is 6 grams per cubic meter.
“Ultra-deep well is a world-class problem. We have all encountered this well. This is the deepest natural gas well on land in China. It is the first time for the brothers to do it. They have to cross the river by feeling the stones.” PetroChina Chuanqing 90011 Drilling Team captain Wang Jian bluntly said that the well was too difficult, and any abnormal noises at the well field made him nervous.
The control of the wellbore trajectory in the horizontal section is the biggest difficulty in construction. First of all, it is necessary to accurately determine where the reservoirs with a thickness of several meters buried several kilometers underground are located, and the “sweet spot” must be targeted to ensure that oil and gas can be found. PetroChina Chuanqing Drilling adopts the self-developed internationally advanced “CQ-IGS horizontal well integrated geosteering technology”, and finely controls the real-time drilling trajectory to stably and efficiently travel more than 1 km in the reservoir nearly 8,000 meters underground.
The “sweet spot” of the reservoir has been positioned. Whether it can ensure that the drill bit keeps advancing in the reservoir will truly test the technical strength of Chuanqing Drilling. During the construction of the horizontal section of Well Shuangyu 001-H6, the drill bit was extended from the ground to 9 kilometers underground through a drilling tool. To control the 149.2 mm diameter drill bit 9 kilometers away to walk along the reservoir is as difficult as threading a needle 100 meters away. Chuanqing Drilling relies on advanced and mature directional well technology to achieve smooth and stable wellbore trajectory in the horizontal section.
Drilling fluid is known as “drilling blood”, which affects the success of drilling operations. Chuanqing Drilling adopts the self-developed oil-based drilling fluid system that is resistant to high temperature and strong plugging. In horizontal well drilling, the wellbore is stable without collapse, the maximum well deviation is 92.16 degrees, and the maximum well temperature is 180 degrees. At the same time, creatively explored the use of oil-based drilling fluid system with high temperature resistance and strong plugging and solid lubricant glass microbeads to successfully solve the problem of directional decompression in ultra-deep wells, providing strong support for the smooth drilling of the well.
The breakthrough of 9,000 meters has overcome complex geological problems such as “ultra-high temperature, ultra-high pressure, and ultra-well depth”, providing valuable experience for the development of drilling engineering technology, and realizing the long-cherished wish of generations of oil people.
“We are all holding back our strength, and we must hit 9,000 meters safely. The Sichuan-Chongqing region has never drilled such a deep well before. We must fight for this first place. Now we have achieved it and set a new record. I feel very excited,” said Song Dongdong, a trainee technician for the 90011 drilling team of PetroChina Chuanqing Drilling.
PetroChina actively explores the “three-high” (high temperature, high pressure, high sulfur content) gas well high-efficiency exploration and development model, and strengthens the drive for technological innovation. Core technologies and equipment such as well completion have achieved major breakthroughs in the field of ultra-deep oil and gas exploration in one fell swoop.
