Real-Time Interpretation Model of Reservoir Characteristics While Underbalanced Drilling Based on UKF

Table 2

Comparative analysis of EKF and UKF estimated results.

Reservoir unit	Reservoir permeability (mD)			Time of convergence to 10% (min)
	True value	UKF	EKF	UKF	EKF
1	250	218	213	21	26
2	500	450	439	21	26
3	350	379	386	18	25
4	150	189	198	25	29
5	50	69	71	27	25