Productivity Study Of Hydrajetting Fracturing In Low Permeability Reservoir

In recent years, with the deepening exploitation work of oil or gas field, low permeability oil resources difficult to mining in reservoir is growing more and more. Horizontal well and hydraulic fracturing technology is an important means of exploitation of low permeability oil. Horizontal well productivity prediction after fracturing is of great significance to fracturing parameters optimization of working system.This paper, based on hydraulic jet fracturing technology, takes horizontal wells in low permeability reservoir as the research object. The purpose of paper is to study horizontal well productivity prediction after the hydrojet fracturing, and the analysis of factors affecting fracturing horizontal well productivity. Considering technique characteristics of hydrojet fracturing:first perforating and then fracturing, and in some cases need to fill holes, this paper also analyzed the impact of perforating horizontal well production capacity and capacity factors. Based on study hydraulic fracturing horizontal well technology at home and abroad, by comparing the advantages and disadvantages and applicable condition of the models, we established the finite conductivity model and fractures equivalent model of the caliper. Through the model calculation and analysis, we got the following understanding and the results:(1) By establishing the reservoir seepage flow and wellbore coupling model, we got perforating horizontal well inflow profile and pressure profile. Example calculation shows that in the low permeability reservoir the horizontal wellbore pressure drop is very small. If within the horizontal wellbore fluid is laminar flow state, the level caused within the wellbore pressure drop is negligible.(2) We established finite conductivity capacity model, considering the various cracks production range, comparing with Langzhaoxin and Fanzifei model prototype, we conclude that fracture diverting capacity is also a important factor affecting horizontal well production capacity, comprehensive consideration of pressure drop and fractures influence can make the end result more close to actual production.(3) We established equivalent caliper fracture model, the model can one-time solve n output without having to simplify the model of fracture, the model does not require equal length and spacing of fractures, and we present a mathematical solution model. This model can effectively discuss various influence factors of fracturing horizontal well productivity.(4) Case analysis of the equivalent caliper model shows fracture distribution under thedifferent fracture number, different crack length, same crack length, and so on and so forthsituations. And the model gives the influence of various factors on the horizontal wellproduction capacity eventually...