On August 24, China National Offshore Oil Corporation (CNOOC) released a news release, China's first 100 billion cubic meters of gas field in the Bohai Sea - Bohai Central 19-6 gas field cumulative production of more than 1 billion cubic meters of natural gas, a strong protection of Beijing, Tianjin, Hebei and Bohai Rim gas demand, to ensure national energy security, optimize the energy structure of great significance. Bohong 19-6 gas field is located in the central Bohai Sea, the average water depth of the region is about 20 meters, the proven natural gas geological reserves of more than 200 billion cubic meters, proven oil geological reserves of more than 200 million cubic meters, is China's first large-scale, fully loaded 100 billion cubic meters of gas field in the eastern part of the country. The gas field is developed according to the program of "overall deployment, phased development, test first", and the test area and the first phase of the development project will be put into production in October 2020 and November 2023 respectively. At present, six offshore oil and gas platforms have been built, and the peak daily gas production has reached 2.4 million cubic meters, and the capacity construction has entered a rapid upward stage. According to China National Offshore Oil Bohai Petroleum Research Institute development geology senior engineer Cheng Qi introduction, Bohai 19-6 gas field oil and gas buried in the depth of more than 5,000 meters of submerged reservoir, the arrangement of the development of the average well depth of 5,598 meters, the depth of more than 6,000 meters of ultra-deep wells up to 20, the deepest reached 6,494 meters, the exploration and development of the engineering and technology requirements are extremely high. In China's oil and gas exploration and development, it is generally considered that formations with a depth of more than 4,500 meters are deep, and formations with a depth of more than 6,000 meters are ultra-deep. The Bozhong 19-6 gas field has now successfully implemented two ultra-deep wells, with formation temperatures exceeding 180 degrees Celsius, bottomhole pressures reaching 56 MPa, and hydrocarbons being stored in cracks only 0.01 to 0.1 millimeters wide, which is equivalent to extracting hydrocarbons from hair strands.
In the face of drilling and mining problems, the oilfield personnel put forward the "folding-fracturing-filling" three-control advantageous reservoir pattern law and prediction method, independently developed high-temperature and high lubrication drilling fluids, and successfully cracked the high downhole temperature, the complexity of the pressure system in the wells, and the downhole tools are prone to failure and other technical problems, which provided solutions for the development of the deep oil and gas reservoirs.
