Modifying the Zeta Potential of Formation Fines Utilizing Chemical Treatment:An Alternative to Sand Control to Increase Productivity: A Colombian Field Application

摘要

Sand production in oil and gas wells is a complex problem that requires a multidisciplinary analysis to arrive at an optimal solution of the problem and thus increases the productivity of oil fields with problems of production of sand. Many operators choose as first alternative,the exclusion of sand,avoiding doing a risk management, which ultimately provides lower index of productivity and in many cases convert the wells with sand problems in unproductive wells.Therefore always be a better option the sand management and take as a last option the sand exclusion,obviously framed within a technical and economic evaluation of alterna-tives. In most cases when we refer to a chemical treatment for sand control,it tends to confuse with chemical consolidation treatments,however a different option,is the application of chemical treatments to modify the zeta potential of the formation fines that has been very successful. Modifying The zeta potential to optimum range,provides a strengthened attraction between the particles to optimally align proppant type,sand particles,fines,etc.,allowing the formation of conglom-erates of proppant,sand,fines,etc.,improving conductivity and control of fines migration. This study focused on the evaluation in the laboratory of chemical treatment(compatibility,zeta potential and rock-fluid testing,etc.),mineralogical and granulometric analysis of sand and fines produced by wells with sanding problems,selection of wells and treatment zones,quantification of costs associated with sanding problems,technical and economic evaluation of the application of treatments in candidate wells,etc. This paper presents the results of the laboratory evaluation of chemical treatment(satisfactory results in compatibility and modification of the zeta potential,permeability returns of over 80%,etc.)and implementation in the well Bonanza 39,located in the Basin of the Middle Magdalena Valley in Colombia,where dropped dramatically the frequency of interventions by sanding problems.Before chemical treatment,the well had a monthly intervention and after nine months of the treatment,has not required intervention,allowing increase productivity of the well.