The Last 50 Meters! My Country's First 10,000-meter-deep Well Drilled Into Strata 500 Million Years Ago

Since drilling started on May 30 last year, my country's first Wanmike exploratory well, Shendi Tak 1, has been drilling for more than 200 days and is working hard to reach 10,000 meters. As of the afternoon of February 16, the Shenzhen Taco 1 well had drilled to 9,950 meters underground. The drill bit was breaking through the barriers of underground hard rocks and heading towards the last 50 meters of the 10,000-meter stratum.

As of February 19, the Shenzhen Taco 1 Well had been drilled in the 9,000-meter formation for 55 days. Due to the ultra-high temperature and ultra-high pressure of the formation, as well as the frequent changes in underground rocks, many drilling tools were fatigued and damaged, making the drilling project very difficult.

Wang Chunsheng, chief technical expert of PetroChina's Tarim Oilfield: Now every meter we drill is really like crossing the river by feeling for stones. Every meter we go down is unknown and full of risks. We are now increasing the density to read underground rocks. Geological information is analyzed and judged every half meter, and drilling parameters are optimized in a timely manner. The main thing now is stability.

After the drill bit reached 9,900 meters, the formation pressure system was very complex, and complex situations such as formation collapse and well leakage began to occur. Since the existing technology cannot accurately predict formation pressure and rock mechanical change characteristics, it becomes difficult for the drill bit to advance.

Wang Chunsheng, chief technical expert of PetroChina Tarim Oilfield: At this stage, we may encounter abnormally high pressure at any time, the vibration of drilling tools is very strong, the anti-deviation tools have exceeded the temperature resistance limit, and it is difficult to control well deviation. We are now paying close attention to every item Once the drilling parameters change, we will immediately analyze and adjust them to explore the optimal drilling technical measures to ensure that the well reaches a depth of 10,000 meters safely.

During the Spring Festival, in the Tarim Oilfield in Xinjiang, my country's first Wanmike exploration well, Shenzhen Tako 1 Well, is accelerating its excavation. What is a scientific exploration well? What technological tools are behind it?

01. my country's first 10,000-meter-deep well drilled into strata 500 million years ago

Scientific exploration wells are referred to as "scientific exploration wells" and their main functions are to explore the evolution of the earth, the origin of life, climate change, disaster prevention and resource utilization. The biggest difference between it and an ordinary well is that the area it wants to explore is an unknown area that has never been drilled before.

The designed drilling depth of the Shenzhen Taco 1 Well is 11,100 meters, and it will penetrate 13 formations from top to bottom. After the drilling depth of Shenzhen Taco 1 Well reaches 9,850 meters, the drill bit needs to be replaced. The new drill bit will continue to drill 10,000 meters at the previous operating location. Since drilling began in May last year, the Shenzhen Taco 1 Well has penetrated 11 formations and set multiple drilling records in succession.

At present, the Shenzhen Taco 1 well has drilled into the 12th formation. This formation has been buried underground for 500 million years. By analyzing rocks deposited in ancient formations, geologists will gain a deeper understanding of the sedimentary evolution characteristics of the Tarim Basin and provide first-hand information for scientific exploration and oil and gas exploration.

According to experts, research has found that the Tarim Basin is conducive to the generation and preservation of oil and gas in deep layers, and exploration practices have continuously broken the lower limit of oil and gas generation. Through oil and gas generation simulation research, it is predicted that petroleum liquids may exist below 9,000 meters deep, and natural gas may exist below 12,000 meters deep. The success of the 10,000-meter deep well will greatly expand the field of oil and gas exploration.

As a strategic succession area for oil and gas resources, deep and ultra-deep layers have become the main areas for major oil and gas discoveries in my country. The Tarim Basin where Shenzhen Taco 1 Well is located is an ultra-deep oil and gas rich area in my country. The total oil and gas geological resources below 8,000 meters exceed 9 billion tons of oil equivalent, accounting for more than half of the country's ultra-deep resources.

It is reported that the natural gas produced from deep formations below 4,500 meters in the Tarim Basin, where the Shenzhen Taco 1 Well is located, exceeded 260 billion cubic meters. At present, the daily natural gas production of Tarim Oilfield is close to 100 million cubic meters. Most of this natural gas is extracted from deep formations seven to eight kilometers underground. The Bozi Dabei Gas Region, as my country's newly developed main deep-earth natural gas production area, has seen its production rising steadily since the beginning of winter.

The Tarim Basin is the largest oil and gas basin in my country, with abundant ultra-deep oil and gas resources. Tarim Oilfield has built five main deep and ultra-deep natural gas production areas in the southern foothills of the Tianshan Mountains and the hinterland of the Taklimakan Desert, with an annual gas production of 30 billion cubic meters.

In order to speed up the realization of new well production capacity, Tarim Oilfield has accelerated the construction of surface supporting system projects and accelerated the improvement of oil and gas gathering and transportation capabilities. The natural gas extracted from the deep strata of the Tarim Basin is collected through the criss-crossing pipelines in the oil field to the first station of the West-East Gas Pipeline, and then transported to Wanli Guomai.

02. 10,000-meter deep wells drive iterative upgrades in petroleum equipment manufacturing

The world's first 12,000-meter deep well automated drilling rig was used in the 10,000-meter deep well. It also used nearly 200 top domestic equipment such as casing, drill bits, and downhole tools independently developed in my country, promoting the iterative upgrade of the drilling equipment industry chain. .

Recently, my country's newly developed highest-grade steel pipes were sent to the 10,000-meter-deep well site and will be used to support the well wall after the well breaks through 10,000 meters. The depth of 10,000 meters places higher requirements on the strength and toughness of oil casing. Drilling tools go down to a depth of 10,000 meters

Once deformation occurs, it will cause immeasurable losses. R&D personnel have simulated dozens of underground high-temperature and high-pressure working conditions and conducted hundreds of experiments and field tests.

Lu Xiaoqing, chief engineer of product design technology of Baosteel Co., Ltd.'s Steel Pipe and Bar Steel Division, said: The steel grade, anti-collapse performance, sealing performance and other key performance indicators of the casing are all more than 21% higher than the highest steel grade casing, and it can be used at high temperatures of 220°C. Environmental conditions, the performance indicators of the casing can still remain unchanged.

In addition, the 10,000-meter deep well drilling has also developed and applied high-efficiency rock-breaking drill bits, elevators with a load-bearing capacity of 1,000 tons, drill pipes with a tensile strength of 942 tons, high-strength metal-sealed coring tools, and drills that can withstand high temperatures of 230°C and high pressures of 175 MPa. A large number of scientific and technological tools such as logging instruments have strongly supported drilling to depths of 10,000 meters.