重钻井液快速混配自动控制系统研制

Research and Manufacturing of Fast Mixing Automatic Control System for Weighted Drilling Fluid

在加重钻井液快速混配装置的基础上,研制了一套自动控制混浆系统,用以弥补人为目测调节浆体密度过程中因迟滞与误判造成的误差。该系统以PID经典控制为核心,采集混合后的加重钻井液密度和液位,与设定的目标密度与液位进行对比,根据趋势自动调节输入口下灰量阈值,以实现加重浆混配密度的自动调配。配备了该套混浆自动控制的装置经过现场工业的实际试测,所配制的浆体密度均匀,比例统一,混合程度高,粘稠度完全达到钻井加重工艺的需要。并且该自动控制装置工作持久稳定,控制精度高,响应即时,对密度变化的趋势判断准确,稳态误差小,抗干扰能力较强,无需人员值守,保证了作业的连续性。由于成本低廉,装配简易,其控制理论与数据在石油钻采,固井混浆中有着广泛的推行空间,可以衍生很多自动混配设备,该装置为石油行业中各种工况混配系统奠定了标准性基础。

An automatic control system is researched and manufactured based on an existing fast mixing device,it is used to avoid errors caused by delay of visual observation of mud density and misjudgment.This system incorporates the core technology of classic PID control,the mixed liquid level is compared with the set density liquid level of weighted drilling fluid to automatically adjust dry cement metering valve according to the measured trend to realize the automatic density mixing of weighted fluid.The field test of a mixing device equipped with this system shows that the mixed mud density is consistent and uniform with high mixing degree,and that it can fully meet the requirements for weighted mud process.Meanwhile,this system can work stably and durably,it has high control accuracy with quick response,accurate judgment of density changes with less error,and it has high capacity of disturbance resistance with unmanned control for a consistent operation.Due to low cost and easy assembling,its control theory and data can be widely applied in petroleum drilling,production and cement slurry mixing,and many derivative automatic mixing equipment can be produced,therefore,it lays a solid foundation for different mixing systems in different operation conditions in petroleum industry.