Research On The Depositing And Scaling Laws Of ASP Flooding Gathering And Transportation System

As the Daqing Oilfield development constantly goes deeper and the sustained stableproduction goal comprehensively promotes higher, alkaline-surfactant-polymer (ASP)flooding, one of the main enhanced oil recovery (EOR) technologies, is very important toimprove the oil production. While, during the application of ASP flooding, the surfacegathering and transportation system, such as oil gathering pipelines and watering pipelines,was seriously deposited and scaled, and lead to the problems of increased pipe resistance loss,rose system back pressure, increased energy consumption, decreased operating efficiency andincreased production cost. So it is necessary to study the composition and formationmechanism of deposition and scale sample, analyze the influence factors and laws ofdepositing and scaling, optimize the production operation parameters and establish anoperation scheme of reducing the depositing and scaling effectively.The ASP pilot area of Xinbei oilfield in Oil Recovery Plant No.4of Daqing Oilfield istook as the actual engineering background. The composition characteristics of deposition andscale sample were determined by means of physical and chemical analysis method, it showsthat the deposition sample mainly contains much wax and the scale sample contains silica,and the formation mechanism was analyzed. The scaling behaviors of Si4+, Mg2+and Ca2+were studied on the base of the analysis of produced water quality, and it indicate that theconcentrations of the ions is decreased with the temperature increase, increased with the flowvelocity, pressure, concentrations of surfactant and alkali increase, and increased thendecreased with the polymer concentration increased. And the influence laws of gatheringtemperature, water cut, pressure, flow velocity and ASP concentration on depositing andscaling in surface gathering and transportation system were studied and analyzed by means ofindoor simulation test. The depositing rate is decreased with the temperature, water cut andflow velocity increased and increased with the polymer concentration increased. And thescaling rate is increased with the temperature increased, decreased with the flow velocity andpressure increased and increased then decreased with the polymer concentration increased.Combining with the study results and the field actual production situation, the applicationeffect of anti-deposition agent is considered to be well and the operation parameter ofgathering and transportation system is optimized.