At 18:38 on September 7, the casing of Songshaoyou 2HF well in Songliao Basin went down to the bottom of the well at a high speed of 200-300 m/h. This marks the successful application of NAPG (polyether aminoalkyl glycoside) near-oil-based drilling fluid technology independently developed by Zhongyuan Petroleum Engineering Company. Sinopec has reached the international leading level in near-oil-based drilling fluid technology, filling the gap in theory and technology of near-oil-based drilling fluid at home and abroad. The successful completion of this well has epoch-making significance for China's oil and gas exploration and development.
2HF is the first shale oil horizontal well produced by water based drilling fluid in China. The successful completion of the well has broken the myth that Qingshale reservoir of Qingshankou Formation in Songliao Basin has been regarded as an invincible "death forbidden zone" for many years, broken through the technical bottleneck that water-based drilling fluid can not safely drill through the long open hole section of pure mudstone, and accumulated valuable lessons for subsequent large-scale development of shale oil resources in Songliao Basin. Test.
The well is a window-opening sidetracking parameter well in Gulong Depression, northern Songliao Basin. The completion depth is 3062 meters. The drilling party is 40486 Drilling Team of China Central Petroleum Engineering Company Drilling Company No. 2. The lithology of the inclined section and horizontal section of the well is grey-black fluorescent mudstone. The tendency of hydration and dispersion of mudstone is serious and the fracture development is serious. The formation is easy to collapse. The formation of the inclined section and horizontal section is drilled by open hole, and the total length of the open hole section is 1508 meters.
_NAPG near-oil-base drilling fluid is used in this well for 1554-3062 meters (long open hole, pure mudstone). The open hole immersion for 165 days before casing running still maintains a strong and lasting wellbore stabilization effect (the collapse period of the same horizon in adjacent wells is only 7-22 days). Except for the spalling block caused by the insufficient support capacity of the wellbore in the early stage, no new spalling block occurs after the density increases, which fully demonstrates the super-strong anti-collapse effect of the system and overturns the traditional idea that water-based drilling fluid has a collapse cycle for a long time.
The system is a new drilling fluid technology independently developed by the R&D team of alkyl glycoside derivatives of Zhongyuan Petroleum Engineering Company for 8 years. The mechanism of the system is similar to that of oil-based drilling fluid, and its performance is the same as that of oil-based drilling fluid. The old slurry can be recycled and reused, which has the unparalleled environmental protection advantages of oil-based drilling fluid.
The system is based on the alkyl glycoside derivative NAPG, which is independently developed by the team. It is formed with other additives. By adsorbing film-forming water-blocking, reverse osmosis water-driving, embedding and tightening the crystal layer of clay minerals, it eliminates the hydration, expansion and dispersion of formation, and traditional water-based drilling fluids and high performance water-based drilling fluids. There are qualitative differences in drilling fluids. The system can resist temperature up to 160 degrees Celsius and its density is 1.2-2.5 g/cubic centimeter adjustable. It has absolute technical advantages such as super-strong inhibition, formation non-mud-making, high lubrication, non-sticking drilling tools and strong plugging. There is no runaway problem of rheological property. The drilling fluid has long-term and stable performance and is suitable for high-active mudstone, mudstone-bearing mudstone and sand-mudstone interbeds. Drilling in the long horizontal section of such collapsing formations and shale gas horizontal wells.
_. The technology system will continue to be widely applied in other relevant blocks and contribute to China's oil and gas exploration and development.