Scaling Mechanism And Control Strategy Of TM Reservoir

TM reservoir produced fluid contains colloid,asphaltene and wax,and oil wells are accompanied with scale formation.The reservoir permeability is low,and scale generation directly affects oil field production.In 2016,there were 36 oil well inspection pumps in TM reservoir,including 9 for scale inspection,accounting for 25%of the total number of inspection pumps;in 2017,there were 37 oil well inspection pumps,14 for scale inspection,accounting for 37.8%of the total number of inspection pumps;in 2018,there were 34 oil well inspection pumps,18 for scale inspection,accounting for 52.9%of the total number of inspection pumps;in addition,in recent years,due to scaling in TM reservoir,the injection pressure has increased,seriously affecting the development effect of the oilfield.Therefore,it is necessary to study the trend of scaling,scaling mechanism,scaling law and Countermeasures in TM reservoir.In this paper,TM oil and water reservoir and near well zone reservoir are taken as the research object,and the prediction of scaling trend of oil and water reservoir,the influence of scaling on reservoir permeability and injection pressure,and the control measures are studied.Based on the understanding of the scaling history and status quo of TM reservoir,firstly,the water samples and scale samples of TM reservoir were detected and analyzed,and it was found that the TM reservoir water samples mainly contain Ca²⁺,Mg²⁺,CO₃^2-,HCO₃^-,SO₄^2-,and other scaling ions.By using the methods of stability index,saturation index and Skillman thermodynamic solubility,the scaling trend of carbonate and sulfate scale in TM oil and water reservoir is predicted,and the predicted results are analyzed.Secondly,through the reservoir sensitivity evaluation and core indoor simulation experiment,the main factors causing the reservoir permeability decline and injection pressure rise are explored,and the harm of different injection water quality scaling to the reservoir is analyzed.The analysis shows that the main reason for the decrease of reservoir permeability under the condition of injecting clear water is the generation of scale,and the pore plugging is caused by the scaling and particle migration of reservoir.If the water quality is not good and the solid content is more,the solid content is the key factor that causes the displacement pressure to rise rapidly.At last,according to the scale formation of TM reservoir,the proper scale inhibitor and complex scale remover are selected,and the reasonable and effective countermeasures are put forward.The experiment shows that SY solid slow-release anti scaling,anti-corrosion and anti wax effect is significant,which can greatly improve the pump inspection cycle;HY complex scale remover can restore the reservoir permeability,and has the effect of scale removal and plug removal for the scale formation.