Research On The Geological Characteristics And Protection Technology Of Carbonate Reservoirs In Zhujiang Formation Of LF15-1 Oilfield

Carbonate rocks are important reservoir rocks,such as minerals,carbonate reservoir pore structure and clastic rock reservoir,damage mechanism is also a certain difference.It is generally believed that carbonate hydrocarbon reservoir damage is mainly the invasion of solid phase and filtrate invasion,stress sensitivity,etc.The author takes for example the carbonate reservoir of the pearl river,on the basis of deepening the carbonate reservoir drilling and completion,optimizing drilling and completion fluid,do utmost reduce drilling and completion of reservoir damage in the process,to provide reasonable and scientific advice,the late LF15-1 oil field exploitation.The preset studay the limestone reservoir characteristics of LF15-1 oil field ZJ10,including the characteristics of sedimentary facies,tectonic characteristics,reservoir lithology,physical properties,pore structure,the sensitivity of the mineral characteristics,has been clear about the late potential damage factors in the process of drilling and completion.Reference to industry standards,evaluated the sensitivity damage size,and through the SEM,studied the damage mechanism.It optimized the LF15-1 oil field horizontal well drilling and completion fluid formulation,on the basis of reservoir geological characteristics,combined with peripheral oilfield drilling.And through the dynamic displacement experiments,the static compatibility and theoretical calculation,evaluated analyses the selection of drilling and completion fluid on reservoir damage size.Make sure that the later period of oilfield development,provide scientific basis for oilfield production in the future production.The Major findings of the studay are:(1)Pearl river group ZJ10 limestone reservoir lithology is mainly micritic biological chip biological limestone,micritic algal boundstone and micritic calcirudite,filler content of micritic matrix.Clay mineral content is 1%?3%,mainly illite and kaolinite.ZJ10 limestone is given priority to with hole in the low permeability reservoir type,reservoir space includes primary intragranular pore,intergranular dissolved pore,intragranular dissolved pore.(2)LF15-1 oil field velocity sensitive damage index was 26.85%on average,the damage degree is weak?medium weak;The critical flow rate of 1.0 ml/min,pore fluid within the critical flow velocity of 0.14-0.15 m/d.Water sensitivity damage index was 31.3%on average,damage degree is weak in the weak??critical salinity is 21000 mg/L.Hydrochloric acid sensitivity damage index was 29.95%on average,damage degree is weak?medium weak.Reservoir alkali sensitivity damage index was 38.3%on average,damage to medium weak;The critical pH value of 8.0?8.0.Reservoir stress sensitivity damage rate of 12.19%on average,stress sensitivity damage.Stress sensitivity damage,core permeability recovery rate>95%.(3)Optimizing the PRD horizontal well drilling fluid,and the corresponding supporting completion fluid system.(4)After optimization of PRD drilling fluid and completion fluid has anti permeability recovery rate is high,low filter loss,low invasion depth,skin factor is low,good compatibility with reservoir fluid characteristics,reservoir protection effect is good.