Development of Film Forming Agent HN-1 and Its Application in Drilling Fluid

Borehole instability and reservoir damage had become the international technical problems of petroleum exploration and development of complicated area, and the water of drilling fluid invading borehole wall and petroleum reservoir was the main cause of borehole instability and reservoir damage. In order to prevent the water of drilling fluid invading borehole wall and petroleum reservoir, domestic and foreign scholars recently put forward the technology of ultra-low permeable drilling fluid. Film forming agent was the key treating agent of ultra-low permeable drilling fluid, the film forming agent (HN-1) was developed, which did not affect properties of the drilling fluid and could decrease the filter loss of drilling fluid applied in Enping 24-2 oil field. Based on this research, ultra-low permeable drilling fluid could be applied to Enping 24-2 oil field. By the methods of testing ultra-low permeable drilling fluid properties, the drilling fluid invasion sand-bed depth, drilling fluid high temperature/high pressure (HTHP) sand-bed filter loss, the pressure-bearing ability of rock core and the ability of reservoir protection were studied. By synergistic effect, HN-1 containing the organic silicate and natural fiber polymer modified by organic amine prevented the liquid and solids in drilling fluid invading reservoir, decreased drilling fluid invasion sand-bed depth and drilling fluid HTHP sand-bed filter loss, improved the pressure-bearing ability of rock core and the ability of reservoir protection. The drilling fluid could decrease reservoir damage to the maximal degree, and it offered efficiency guarantee for exploitation Enping 24-2 oil field.