| The extended reach wells (ERW) can provid with a series of economic and social benefits, such as reducing the expense in the oil reservoir exploring and exploiting, shortening the time of field constructing, quickening the capital reclaiming, dropping the soil wasting and environment polluting and so on. The ERW has become one of the important means in the oil reservoir exploring and exploiting. As the number of the ERW increase, the hydraulic fracture ERW has become one of the important means for the ERW. Because the hydraulic fracture ERW is a novelty application field, the study of some fundamental theory on hydraulic fracturing the ERW is quite not plenty and realized clearly. Using the rock's linear elasticity theory, considering some influencing factors such as the treatment conditions, the fracturing fluid filtration effect, porosity pore pressure and so on ,the paper studies the stress field around the ERW wellbore the breakdown mechanism of rack and the breakdown pressure in the way of barewell and perforated completion respectively, which related to initiating fracture. So it provides the theory principle for successfully fracturing the ERW. And according to the size of the breakdown pressure, in combination with well trajectory string structure and preset pumping program of the ERW, the model of fracturing slurries movement interface in ERW wellbore was defined. Through detecting real-time fracturing slurries interface position and the varying property parameters of every segment fluid in the wellbore and its corresponding changes of rheological parameters, we can calculate the surface treatment pressure which providing a crucial parameter for fracturing design and operating process. At the same time this paper also present the methods of obtaining the rock's elasticityparameter-the elasticity modulus, Poisson's ratio by using triaxial compresstest and the model of well logging interpretation. These parameters are very vitalfor hydraulic fracture design. |
PDF Full Text Request