Optimization Of Water-soluble Temporary Blocking Agent And Studying The Property

The Yuanping A well area is located in the Daqing Changyuan Putaohua structure of the central depression in the Songliao basin,which is Daqing increase production of important area.The reservoirs are characterized by low porosity and low permeability,hydraulic fracturing has become an important means to improve the production of such fonnation.In the early stimulation process,due to unknown understanding of the reservoir and fracturing design of the fracture cluster spacing is too large and other reasons leading to a large number of remaining oil failed to effectively use,so refracturing was put on the agenda.The key to the success of refracturing construction is to block the original fracture.In this paper,for effectively guiding on site refracturing implementation,the relevant experimentswere carried out to optimizeplugging agent ratio.The temporary plugging performance and the effect on broken down of the temporary plugging agent were studied for sand-pack fracture with different permeability.In the extensive research on temporary plugging technology and physical simulation experimental research on the basis of the status quo,this paper has optimized the formulation of plugging agent through manyexperiments.Combined with Daqing formation temperature and pressure characteristics,through orthogonal experiment to test the different components of the system temporary plugging and relieving damage performance.For the follow-up experiment and site construction to provide a reliable material,the influence of each component on the performance of plugging agent is studied by using variance analysis and bit level trend analysis.So as to optimize the temporary plugging agent system ratio which is suitable for the formation characteristics of Yuanping A well area(gelatin 56%,sodium carboxymethyl cellulose 25%,sulfonated pitch 11%,glycerol 15%).The factors to be considered for on-site construction are matched with the experimental conditions,this paper defines the parameters such as the temperature of the indoor experiment,the sanding concentration,the closing pressure and the displacement flow.The experiment scheme of reasonable temporary plugging and relieving damage is designed,and the influence of different slugslength and backflow pressure and other factors on the temporary pluggingand relievingdamage performance of different permeability capability fractures is studied.In this paper,the use of improved after the test device to optimize the water-soluble plugging agent system to carry out plugging and relievingdamage performance analysis of factors,it was found that under the condition of indoor experiment,it is effective for the sanding fractures with the flow conductivity of 15?30D·cm,the slug length is in the range of 1.0?2.0cm and the flowback pressure range is between 2.5?4.OMPa of the plugging and the effect on broken down,and the influence of experimental parameters such as slug length and backflow pressure difference on the plugging and relieving damage effect for different flow conductivity of sand filling fractures were analyzed.Based on the recommended parameters of indoor experiment,the experimental optimization parameters are transformed into the recommended parameters of the site construction by similarity principle.On this basis,a set of reconstruction scheme and process suitable for the temporary plugging and fracturing construction of Yuanping A-4 well are put forward,and successfully implemented in the field.