Research On Compound Perforation Process Simulation And Capacity Forecasting Method

Perforating is an important step in the process of exploration and development of oil and gas fields, and it has been attached great importance by petroleum engineers for a long time. To increase oil and gas well production rate, the engineers have carried on a large amount of research, and presented a lot of new perforating techniques. Since the1990s,the petroleum engineers has put forth the propellant-perforating, which has increased the production significantly. In order to further understand the mechanism of propellant-perforating process, and recognize the main factors influencing propellant-perforating results, the paper is to study the process simulation of propellant-perforating and productivity prediction, thus to provide guidelines for the design of perforation operations, and to develop new perforating technologies.Based on the characteristics of propellant-perforating, this paper mainly studies the act process of the technique inside the gun, anulus and formation, and establishes the productivity prediction model. On the basis of these, the computer software about propellant-perforating optimization is developed, which has been used in the optimization of propellant-perforating completion of Daqing Oilfield, providing very good instructions for the plan design of the perforating operation and the development of new types of the technique. From the research of this paper, the achievements have been obtained as follows.(1) Numerically simulate the process of the propellant-perforating With the study of explosion(deflagration) flow field of the explosive(fracturing explosive, perforating charge) in the complicated calculation domain, the change process of pressure with time is numerically simulated, and the action of explosive inside the gun, annulus and formation is described. Compared with the actual measurement data, the calculation results have small errors, quantitatively recognizing the mechanism of the propellant-perforating.(2) Propose the design method of the critical explosive load With the numerical simulation of damage and fracture of multi- material and multi-structure under the effect of impact load, the critical damage condition of the perforating gun and casing, and the critical explosive load during the perforating process are determined, which provides a theoretical basis for the rational design of the explosive load in propellant-perforating. (3) Initially present an analytical method for the effect of propellant-perforating on formation fracturing With the unit failure technology, the damage process of the formation rock under the loading is numerically simulated. The formation of the fractures are described, and the fracture shapes and distribution law are also obtained.(4) Establish the calculation method of the propellant-perforating productivity Combined the conditions of the fractures, the filtration equation of propellant-perforating is established, and the productivity of a single well can be predicted.(5) Develop a set of optimization design software for the propellant-perforating Using VC++, and under Windows, the highly commercial prediction and optimization design software has been developed. The software has full functions, and it is easy to input, output; it has the function of automatic generation of reports. The interface is friendly. The software has achieved very good results in the application of Daqing Oilfields.