Horizontal Well Fracturing Design And Operation Of Shale Reservoir In YuDong Area

Shale gas as a kind of important unconventional resources,is very important for China’s energy security and supply.In shale gas,shale gas by adsorption and dissociation in dark mud shale or high carbon mud shale and sand inclusion,silty rock strata,was characterized by the author classifies the patterns"in situ".Shale gas reservoirs have unique storage and low permeability features,different from the conventional gas reservoir exploration technology.In order to achieve economic development,horizontal well fracturing operations to increase production must be select to form a crisscross of fissure network system.Releasing free gas and adsorbed gas in the reservoir to improve the shale gas well production.Therefore,the goal of shale gas horizontal well fracturing design is according to the reservoir geological characteristics using reasonable engineering measures to form a certain number of network system in the reservoir.On the basis of predecessors’research,based on the experience of the north American advanced,Research on geological characteristics of shale reservoir in YuDong,What kind of engineering approach to take is the key to realize the effective development of shale gas reservoir.The Long maxi-Wu feng group reservoir sedimentary thickness is big,rich in organic matter.The sedimentary environment is conducive to the preservation of organic matter.Explaining gas zones with 4 layer,a total of explanations 48 m.There was no water layer in and nearby the reservoir,water layer mainly concentrated in Mao kou and Qi xia group.Reference for north American shale reservoir geological characteristics of indicators,according to the research of the predecessors,through data analysis and laboratory experiments,To evaluate shale reservoir in Jiao Shi town area:organic carbon content of TOC with an average value of 2.54%is greater than 2%,rich in organic matter.Vitrinite reflectance R_O with an average value of 2.65%is greater than1.3%,the thermal evolution degree of organic matter is moderate.The average porosity is 4.61%greater than 2%,the average permeability value of 21.94×10^-3μm² is greater than 10^-4μm²,the density is 2.58 g/cm³.X-ray diffraction mineral analysis brittleness mineral content 65.8%,clay mineral content is 22.6%,montmorillonite swelling clay mineral of clay minerals such as 55.4%of the total,swelling clay mineral content is higher;According to the revised Richman method to calculate brittleness index50-62.4%,high brittleness index;Poisson’s ratio 0.198<0.25,the young’s modulus of31558 mpa>20000 mpa,the horizontal stress difference coefficient of 10.02%,is conducive to the formation of complex joint network.The maximum horizontal principal stress direction was east-west.Reservoir fractures are relatively well developed.Shale reservoir of Jiao Shi town area with high abundance of organic matter,natural fracture are relatively well developed,brittle mineral content is higher,high young’s modulus,poisson’s ratio is low,is conducive to the formation of the complex joint network.According to the characters of shale gas horizontal well conditions,the hydraulic pumping bridge plug perforation technology was selected as piecewise perforating technology.According to the cracks induced stress model,when the cluster spacing between 20 to 30 meters can realize interference between seam to increase the complexity of the fracture.Through productivity optimization to select effectively supporting half fractures length.The first paragraph in horizontal well use coiled tubing to perforate 2 clusters,the rest of the paragraph by pumping bridge plug segmental perforation 3 clusters,Optimizing the position perforating clumps and perforation.According to shale reservoir brittleness index in Jiao Shi town area50-60%,choose mixed fracturing fluid system gliding water+linear glue as fracturing fluid.Summarizes the different content of brittle material and the relationship between the fracturing fluid and proppant,evaluating the slick water,linear glue water applied in the field in laboratory.The reservoir closure stress was45mpa,according to the proppant crushing rate test,using the powder pottery 70/140+resin coated sand 40/70 yard 30/50+resin coated sand as proppant,construction parameters was optimized by using Meyer2010.Formulate the shale reservoir horizontal well fracturing scheme.According to Jiaoye1HF well fracturing operation,under the condition of well conditions and equipment to allow as much as possible,improve the capacity and the static pressure in the seam to realize the aim of volume fracturing.In order to meet the requirements of shale fracturing of large capacity long time operation,Optimization of surface process layout and multi fluid supply system,improved fracturing wellhead.By injecting lead acid to reduce the construction pressure,low sand ratio of powder sand slug to deal with shale reservoir,to achieve greater volume of reservoir reconstruction.With abnormal pressure shale reservoir,using linear glue to fully form crack.Because of the proppant gravity differentiation in the horizontal interval,puts forward a method to determine the amount of proppant replace.Set up a set of suitable fracturing design for shale reservoir in YuDong area.For fracturing design of similar geological characteristics of shale gas reservoir has a certain guiding significance.