加重钻井液快速混配自动控制系统研制

Development of Automatic Control System for Fast Mixing of 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。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。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,因此该装置的成功为石油行业中各种工况混配系统奠定了标准性基础。

Based on the rapid mixing device of weighted drilling fluid, a set of automatic control mixing system is developed to de-crease the error of slurry density caused by human hysteresis and misjudgment in the regulating process of slurry density. The systemacquires the density and liquid level data of the weighted drilling fluid by the classic PID control, the acquired density and liquidlevel data are compared with the target values of weighted drilling fluid density and level, and the input threshold of the addedweighting material is automatically adjusted according to the trend to achieve the automatic adjustment of the weighted drilling fluid.The field tests show that the prepared drilling fluid slurring is of uniform density, and its viscosity can meet the requirements of theweighted drilling fluid. The automatic control device can consistently and steadily operate, and it has high control accuracy and highresponse speed. Its judgment of density varying trend is accurate, its stable error is little, and it has strong anti-interference ability. Itcan work without personnel on duty to ensure the continuous operation. The control theory and data of the automatic control mixingsystem can be applied to the mixing of drilling fluid and cementing slurry due to its low cost and simple assembling. The automaticcontrol device can derive into many automatic mixing devices, and the successful development of the automatic control device lays thestandard foundation for various mixing systems.