Study On The Technology Of Horizontal Well Sealing In Low Permeability High Temperature Gas Reservoir

C gas reservoir, with its high reservoir temperature in target formation, is typical for its low permeability, and adopted horizontal wells to exploit. But along with the production, gas yield failed to reach prospects. Based on previous researches, the main reason resulting in low production rate is due to the formation damage. Conventional plug removal measurements had been applied in field, nonetheless it could not improve the situation as expected. Therefore, it is necessary and urgent to analyze damage mechanisms and optimize stimulation technology. On account of well completion method and the limitation of exceptive construction offshore environment, put forward special requirements on technology. In full consideration of the reservoir conditions, productivity, casing program, and equipment capability, the main work and contributions that have achieved in this thesis can be summarized in the following four aspects.According to field data, investigation shown that target formation owns poor petroleum physical properties, low porosity-permeability and the heterogeneity is strong. The result of sensitivity evaluation experience and the simulation evaluation of drilling and completion damage to formation reveal stimulation technology and stimulation fluid system to meet the special requirements.Performance of acidizing fluid system has been measured through experiences that indicates, when compared with old ones, this composite acid system has a remarkable characterization of high effect, which contains composite breaker, non-acid and acid plugging agents.Composite stimulation design was given to horizontal well in C gas reservoir, then composite and non-acid plugging removal agents were optimized in order to treat the damaged well suiting the remedy to the case by means of both physical treatment and chemical technology. A computer program of three dimensional casing program model on fluid propagation of horizontal well process has been developed to simulate the flow velocity distribution under different simulation parameters using Fluent software, which not only improve the accuracy of velocity distributions analysis, but also gets the enlightenment for acidizing fluid uniform distribution design and optimization of process parameters.In-depth stimulation design was also given to horizontal well in C gas reservoir, meanwhile, a new kind of retarded acid system was put forward and acquaints with its advantages of good retarded effect, clay anti-swelling and corrosion inhibitor characteristics, consequently, through the experiences of the core plugging indoor, it shows that there is an significant increase in the permeability.By all of the above researches, a composite stimulation technology in accordance with theoretical analysis, laboratory test and numerical simulation is discussed. Further understanding of the target reservoir is achieved. Moreover, provide a scientific guide for the evaluation of composite stimulation design to horizontal well in C gas reservoir.