化学药剂用量不正确的影响

Problematic and costly repercussions can occur should the inhibitor dosage be over or under the optimum application rate. Reasons for under- or overdosing are often tied to chemical injection flowmeter accuracy, which can be heavily influenced by the properties of the injected chemicals. Under injection of treatment chemicals can result in scale or paraffin buildup in well production strings or pipelines, 降低产量. 如果水垢或石蜡在生产线上存在较长时间, 这口井可能不得不关闭以进行批量处理, 产生递延生产和干预成本. 在注入缓蚀剂的地方， 海底脐带缆、立管和流管(SURF)设施 can, in severe cases, be taken offline until failed components are replaced.

在用药过量的情况下, chemical excess costs can be significant and the additional chemical tanks take up valuable deck space on the platform. 例如, a company could spend more than US$1 million to overinject just one well over the life of the field. Furthermore, excess levels of LDIs in the export crude may affect its value at the refinery. 在一片田地的生命周期内, accurate flow measurement and control of LDI injection could reduce operational expenditure by tens of millions.

计量ldi的挑战

LDI注射, particulate block-age is a recognized cause of CIMV failure; this blockage is partly caused by the extremely low required injection rates, 有时小于0.5 L/h [3.17 gal/d] and the fact that particulate contamination can be introduced into the chemicals during transport, 存储, 海底分布. These particulates can block moving parts inherent to many flowmeter and CIMV designs.

Traditional flow measurement technologies used in subsea chemical injection metering valves typically use Venturi-type flow measurement. Inaccuracies in flow measurement can stem from particulate contamination and blockage in the CIMV and from the fact that CIMVs are engineered years in advance of being put into service, 通常对要注射的化学物质了解有限. Such events render the CIMV as being not properly tailored for the chemicals being used, 并最终, 潜在的系统性能不佳.

CIMV流量计设计的新曙光

The latest low-flow CIMV flowmeter design delivers accuracy better than ±2% of reading for LDI injection compared to the industry standard Venturi-type flowmeter that may only deliver accuracy of 5-10% full scale. 2016年OTC上市, the new Cameron PULSE LF low-flow ultrasonic chemical injection metering valve features a microbore nonintrusive, 视线超声波流量计. 无活动部件, 该流量计可提供耐碎屑流量测量, 是否具有非常低的天然压降，与化学无关, 并且不需要海底过滤. 开发用于解决完整的LDI化学注入组合，从0.25l /h ~ 600l /h [1.6 ~ 3800加仑/天], 该流量计与节流阀结合在闭环控制中, providing a self-regulating device requiring only one user-defined input—low rate.

The PULSE LF CIMV's flowmeter addresses the key limitation of present LDI chemical injection technologies—sensitivity to blockage. 该流量计具有颗粒容忍度, meaning that contaminated fluid can easily pass through the unrestricted flowmeter tube. It also provides consistent high accuracy of reading independent of changes in chemical properties such as viscosity, 可靠测量化学抑制剂的流速. Real-time feedback from the flowmeter enables autonomous control of the throttling valve, maintaining a user defined injection rate set point indefinitely regardless of up- or downstream system disturbances.

包装为rov可回收设备，带有机载诊断, the PULSE LF CIMV enables full inhibition without the risk of under- or overdosing. Operators now have the option to reliably deliver LDIs via cost efficient subsea distributed chemical injection systems with precision regardless of chemical properties or contamination, giving them the option to make chemical decisions independent of the installed hardware.