| Hydraulic fracturing for well stimulation in the volcanic reservoir is a new problem of the world,having no grown-up mode.During fracturing in volcanic reservoir,the difference between volcanic reservoir and homogeneous reservoir is great,because natural fissures growed and regional structure variation cause high filtration in fractures,large pressure gradient of pump,nearwell high friction resistance and multi-factures.The mechanisms on volcanics fracture of Niudong volcanic oilfield,are very different from sandstone-formation fracture,exhibiting at technical puzzles such as high stress,high leakoff rate,high contortion in fracture and fissure's hard-controlling.This difference results from the complication of its lithological association and reservoir structure,the great heterogeneity of its osmose,oiliness and mechanical character.Fracture technology of full term gravel input compaction method combine fracture and geology of fractured rock in Niudong oilfield with engineering feature innovation, in view of brand new technology concept of fractured rock.The main principle is introduced rock mass mechanics view-point,in the course of hydralic created fracture, applied optimum technology of fracturing fluid,proppant and operation parameter, expanded low angle natural discontinuity,by means of decreasing filtration of full term gravel input and blocking up fracture,formed booster cavity of hudralic main fracture, improved net pressure of fracture cavity,increased structural surface expansion and extended distance in the near wellbore and far wellbore,formed wellbore,linked up near wellbore or far wellbore to accumulate structural surface,formed fracture diversion system with filtering flow channel function,at the same time,increased filling thickness, decreased barrier brittle fracture and proppand embedment.The paper mainly consists of five sections.The first section is Niudong oilfield geology and reservoir feature research,stressly research rock and reservoir mode,oil storage mode and partition filtering flow mode.The second section is applied rock martix mechanics theory,research engineering feature of Niudong volcanic fractured rock, mainly research structural surface feature cause effect on special mechanics of hydralic created fracture,such as brittle fracture effect,embedding effect,filtration effect,earth stress screening effect,sensitivity damage action.The third section sum up present stiuation of volcanic reservoir fracturing technology and earlier days fracturing technology application in the Niudong oilfield,according to sandstone fracturing mode, mainly analyze existing high sand bridge ration of fracturing operation in the earlier days of Niudong oilfield.The fourth section research hydralic created fracture supercharge pressure cavity mechanics of fractured rock mass,mainly analyze inadaptability of conventional fracturing theory for continuous medium,created fracture of booster cavity formation and extended mechnics,G functional derivative diagnosis multi-fracture equivalent filtration.The fifth section research field application technology of full term gravel input compaction method,sum up particular mechanics of created fracture and filtration of volcanic rock fracturing and three kinds of operation mode,demonstrate fracturing design and operation technology and application.Application in volcanic oil reservoirs of Niudong demonstrates that this technology has efficiently resolved conundrums of volcanics fracture such as high sanded-up ratio,high charge for using liquid,low sand ratio and brief effective period, shows that the success rate of fracturing and efficiency of hydraulic fracturing's liquid increases significantly with obvious production increment and large financial benefit, implying that the technology worth theoretically and realistically to promote the application of hydraulic fracture in naturally fractured reservoirs or improve the massive fracturing treatment and development of volcanic reservoir.
|
PDF Full Text Request