| Hydraulic fracturing playes a key role in the field of developmenting the very low permeability Gas field abroad. Through large-scale fracturing technology,the gas field with no exploitation value could turn into considerably reserves. As the main measures of increaseing the productivity and injection,Hydraulic fracturing has been widely used in the development of low-permeability oil and gas fields. It can improve flow conditions of the nearby Bottomhole to improve productivity. In the United States,30%of the crude oil production is getting by fracturing. While in our country,yields obtained by reforming hydraulic fracturing gradually increase. Thus, the hydraulic fracturing becomes an important means to exploration and development the very low permeability gas field. Its development is main reflected in the material and fracturing construction program, for instance fracturing fluid, proppant fracturing design, the seam high control technology and end sand fracturing. It makes progress quickly in the above aspect. However, seeing from he fracturing effect, the same kind of sedimentary facies in the same manner fracturing fracturing, the result will appear larger differences. It indicates that the hydraulic fracturing development of oil and gas reservoir effect is not only related to fracturing way, but also has a close relationship with geological characteristics and fracturing layers.this thesis takes the P1h8and P1S1fluvial sedimentary reservoir as examples, studying the effect of fluvial sedimentary reservoir to Fracturing effect systematicly. Mading clear stratigraphic framework and spatial distribution by layer meticulous Contrast.Structure studying indicates that the study area is mainly a low-amplitude monoclinal structure, north and east higher, south and east lower. The overall structure is simple but possess inheritance. Relying coring wells, carried out sedimentary facies determining and Single well facies Dividing, identified the P1h8as the braided river sub-phase deposition,it developments watercourse, heart Beach, overbank and floodplain micro facies. But the P1S1is meandering river deposition, it developments watercourse, marginal bank, overbank and floodplain microfacies. Sandstone contour map and Single well facies data. Completion forecasting Plane phase space distribution, it shows that the study area is mainly the channel deposits, heart Beach and marginal bank relative agenesisly. Subsequently, establishmenting the P1h8braided river depositional model and P1S8meandering river depositional model. Finally, through Statisticing the production data of development wells fracturing,combining with the structer position, the sedimentary reservoir type, thickness as well as material characteristics of the development wells, summarizes the impact of the deposition to the fracturing production. These effects are reflected in the following aspects.First favorable sedimentary facies is mainly watercourse, marginal bank, heart beach these better physical properties of sedimentary reservoir, fracturing effect relatively better.,And fracturing of overbank deposition is worse, for the same type of deposition facie, Sedimentary reservoir with relatively high value of porosity and permeability has a better effect of Fracture. Second, favorable sedimentary facies has a lower value of average fracture pressure, higher Structure position has a better effect than the lower structure position. Horizontal well has a better effect than other types wells.The effective thickness of the gas is about10meters with Small span will achieve maximum capacity effect. The amount of sand is between39Cubic meter and65Cubic meter, the Fracturing effect is very good.The study enrichs the theory of low permeability gas reservoir fracturing development, laiding a solid geological foundation to the well selection, area selection of the Su-10gas reservoirs. The study result also Provides reference and guidance to Ordos Basin and similar reservoir’s fracture. |
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