Optimization Design Of Perforation Parameters Based On Logging Information

Ordos basin yanchang formation oil reservoir belongs to typical compact oil reservoir and its industrial productivity can be obtained only through fracturing. The design of fracturing scheme plays a more important role in reservoir reform. During reservoir reform perforation operation is the first step of fracturing. Perforation is the only way to opening the way between the reservoir and the well. Fracturing operation can be performed smoothly after perforation operation. Logging technology as an important means to evaluate oil and gas reservoirs and perforation perforation layer selection and optimization of geometric parameters also have important guiding significance.The thesis develops the following researches centered on Ordos basin Yanchang formation compact oil reservoir: ①Establish the mechanical parameters of regional reservoir rocks, the calculation model of crustal stress and the rock mechanics and stress section of typical wells;②Conduct statistical analysis of the stratum parameters, fluid parameters, rock mechanics crustal stress parameters, perforation and formation testing result database in the working area; study and conclude the perforation method and parameters suitable for Yanchang formation oil reservoir type, offering reference for further optimization of perforation design; ③Develop and use compact optimization software, and using software developed 25 wells were perforated parameter optimization. And the following research results and knowledge are acquired:(1) The perforation optimization technology of the reservoir with low porosity and low permeability must be performed with fracturing capacity increasing reconstruction technology. Perforation optimization scheme needs not only to determine the perforation geometrical parameters including bore depth, bore diameter, phase position and bore density etc but also optimization of the perforation position. Based on the geographical characteristics of compact oil in Longdong area of Ordos basin, a practical method That based on the comprehensive evaluation index ZB optimization Perforation horizon for optimization of perforation position is proposed after research and exploration.(2) In accordance with the change features including amplitude of deep, medium and shallow investigate electrical resistivity curves (conventional double induction, double lateral and array induction as well as lateral) and morphological differences, calculate the invasion depth of mud point by point and layer by layer; estimate the depth and degree of drilling fluid pollution reservoir stratum by reference to the empirical correlation between invasion depth and pollution depth and offer the invasion and pollution section of a single well, providing important basis for the optimization design of perforation parameters of compact oil reservoir and its productivity calculation. According to the results of 25 wells show Chang 6 Layer have lager Invasion depth and pollution depth as Chang 7 and Chang 8 layer,it is recommended to use a large aperture deep penetration perforating way.(3) Perforation optimization design must thoroughly consider the direction of regional crustal stress, the stress section and the type of the reservoir and the use of perforation technology and perforation equipment; perform the optimization design of the perforation parameters and perforation ways of different well types; use optimal schemes to enhance the perforation effect, strengthen the effectiveness of fracturing construction and improve well yield.(4) The well logging interpretation application called LogToop developed for the perforation optimization design of compact oil reservoir works stably and has complete functions, Including ground stress calculations, preferably perforated interval,perforating position is preferably, mud invasion depth and extent of the contamination and to calculate a total of five perforation parameter optimization module it excellently makes up for the deficiency of conventional perforation optimization tdesign technology and broaden the new application of logging information in compact oil high efficiency exploitation projects.Through above-mentioned research work, the engineering application scope of logging information is broadened; the perforation segment is optimized and the reservoir is developed with high efficiency, forming a series of effective methods and technologies for the optimization of perforation parameters of compact oil deposit.