Software Development Of Diagnosis And Control Measures Optimization Of Near Wellbore Plugging

Formation damage exists in all aspects of reservoir development, which will reduce the rate in production wells and injection wells, affect the establishement of development programs, decrease the recovery ratio, and increase the exploration cost for removing the plug in the reservoir. Therefore, in the course of reservoir development, effective protection mearures should be taken. And establishing reasonable prevention and control mearures is based on the evaluation of the damage extent, then the damage extent assessment and the research on the prediction technology are of great significance.Traditional assessment method is to evaluate the skin factor derived from well testing.However, this skin factor from a well testing is a sum of skin factors caused by a number of elements and it is not very accurate for evaluating the contribution of a net harm to the reservoir. Therefore, this paper does some research on the well testing method and division method of skin factor, of conventional wells, low permeability reservoir wells, vertical fractured wells with limited conductivity and injection wells. By calculating the skin factors casued by partly penetrating the reservoir , well deviation and perforation, the skin factor of the net reservoir damage can be got by the division of the well testing skin factor.However, in actual production, not all wells have carried out stress testing. Moreover, these testings can just get the total damage extent and can do nothing about the damage radius and the damage extent for every element, and can not decide which damage is greater. However, the detailed information of formation damage such as the main type of the damage and the damage extent is essential to the type selection of the block remover, the usage of the block remover and the process design. For these reasons, based on the reference to the articles at home and abroad, this paper makes use of the fundermental principles of energy conversation, mass conversation, permeation fluid mechanics, and thermodynamics of inorganic and organic chemicals. Consequently, the quantitative mathematical models on diagnosis, prediction and treatment evaluation of near wellbore damage are set up. And it comes up with a method for evaluating the control measures and the block removement effect concerned on each damage type. With the help of the combination of mathematics and computer simulation technique, a software systerm of diagnosis, prediction and treatment assessment of the near wellbore damage is researched and developed, forming a systematic method and process from the damage diagnosis to prediction ways. The tests indoors and the primary field application have shown that this software has a relative high precision of prediction.