A New Method And Theory of Improvement Oil Recovery

Abstract Stable oil production and water control are necessary long term strategies in the world oil fields, and they require more finding each year. Presently, reservoir of bottom water and gas cap development results with horizontal wells are considered satisfactory, but bottom water and gas cap breakthroughs in oil fields are still not controlled. The wells have much more water effect on oil well conventional production which presents difficult technological problems and prevents development of horizontal well technology when water breakthrough into oil wells. This paper presents a mechanism to control bottom water and gas cap breakthroughs into wells during oilfields development. In addition, this paper establishes a new theory of elimination of water and gas into oil wells. Further, this paper presents several methods to eliminate oil and gas from oil wells. By applying the theory and methods we can develop and produce oil and gas reservoir of low permeability, special reservoir and developed reservoir of the high and middle cut stages. This can prolong the period of oil production without water and gas interference improve and enhance oil recovery and allows the greatest economic benefits from oilfields. Introduction There are three stages that are production of freewater, low water cut and middle-high water cut during oil producing. Oil well technology of stable oil production and water control were used that are chemical methods and machinery methods, they are not an activate methods. Water control is multivariate problem is very complex, it result in production cost rapidly increase for the manager, the engineering problem of the environmental protection and water treatment will change bigger, mechanical efficiency and oil recovery will change lower. Why are Oil well produce water? Previous scholars had put great energy into this problem, they thought main reason was coning of bottom water and figuring of edge water. Therefore, coning and figuring should become an important research project on reservoir engineering since Muskat. Scholars pay attention to forecast critical oil production rate and time of water breakthrough into oil well. Resent years, due to horizontal well technology raise, the scholars studying cresting of horizontal well is still base on coning of vertical well. But focus on predication of coning /cresting of bottom water. This paper study a mechanism of bottom water and gas cap breakthrough into oil well. According to the critical condition presents how to eliminate bottom water and gas cap breakthrough into oil well. This method's application will expect injection new life into fields of oil and gas in the world. Coning / Cresting and Critical Oil Production Rate Reservoirs surrounding exist pressure drop when we produce oil from reservoir. If the drop exceeds hydrostatic pressure differential, oil will was produce from reservoir into surface We assume there is a bottom laying under the reservoir, Oil and water Contact would rise in shape approximately a cone, hence the called "coning" (Fig. 1) The coning gradually rising when oil production rate is increase, and exceed certain production rate, the cone shape will rise well bottom in this case, much more water to enter oil well.