The Application of "Inflection Point" Technique in Measuring Earth Resistance of Anode Groundbed for the Pipelines Buried in Desert Area

The authors consider that in accordance with the basic principle of earth resistance, the "real earth resistance" can be measured when the "ground-reference-plane within the groundbed and auxiliary earth anode" is found out. To apply this principle to the measurement on the earth resistance of anode groundbed for the oil pipeline buried in high resistivity area (desert area), a new measurement method is presented, that is, only after finding out the "inflection point" within the potential field between the anode groundbed and auxiliary earth anode can the "real earth resistance" be measured. This new method is successfully applied in the Western Libya Oil Pipeline, and meanwhile the "hyperbolic curve inflection point" technique derived from the "inflection point" technique is developed. The "inflection point" technique is demonstrated on the theory and practice in the earth resistance measurement of large-scale anode groundbed, which solves the troubles in low accuracy readings and suitable to the measurement on the earth resistance of anode groundbed for oil and/or gas pipelines in desert or serir (gobi) areas without landform's limitation.