The Research Of Hydraulic Deep Penetration Technology

In the low permeability reservoirs, there are formation damage in varying degrees exist in near-wellbore of oil and gas wells, formation damage cause the output of oil and gas wells decline. For improving the permeability of contaminated oil and gas near wellbore area, people have carried out a lot of useful exploration. Compared with conventional shaped perforation, hydraulic deep-penetrating perforation technique have advantage as follow: can jet more depth and lager pore diameter, have non-compacted zone and less pollution, so this method is gradually concerned by domestic and foreign oil company. And related research and application in the past 20 years have proved that hydraulic deep-penetrating technology used in oil well perforation has an important significance in oilfield output and enhance oil recovery.With the extensive application of hydraulic deep-penetrating perforating technology, there are some focal points need to be studied. Such as the current pore diameter is not big enough, and perforation distance is not long enough and so on.In order to fundamentally improve the capacity and efficiency of perforation, and further increase oil production, in this paper, hydraulic deep-penetrating nozzle will be researched, and the major tasks are as follows:(1) Create three-dimensional small nozzle jet model, analysis the impact of nozzle structural parameters to jet performance, to get relatively reasonable structure of single-hole nozzle.(2) Establish three-dimensional model of multi-hole nozzle, and carry out the flow field analysis. Focus on the impact of jet flow field, due to the different position and angle of the slant-hole in multi-hole nozzle.(3) Establish self-feeding nozzle model, and carry out flow field analysis. Focus on how to match location, angle and diameter of before and after holes and other parameters, and verify that the nozzle designed in the paper have the ability of self-feeding.(4) Using FSI method to have water jet breaking rock simulation for fluid-structure interaction. In the post-processing the relative relationship of the jet flow field and the stress in the rock interface can be simultaneously observed.(5) Using SPH method for the first time to have dynamic analysis of water jet breaking rock.(6) Based on four methods as follows: the Lagrange method, ALE method, SPH method, and SPH coupled with Lagrange method to simulate water jet breaking rock. The results show that, SPH coupled with Lagrange method is more appropriate.(7) Using SPH coupled with Lagrange Method for structural optimization of multi-hole nozzle, get the relatively reasonable model of multi-hole nozzle.In this paper, a variety of patterns of nozzles are proposed, and within and outside flow field of nozzles are studied. And water jet rock-breaking is researched basing on a number of ways. At last, the paper optimize the structure of self-feeding nozzle which have the ability of self-advanced, and this nozzle can be applied to water deep-penetrating work.