Nanoplugging Performance of Hyperbranched Polyamine as Nanoplugging Agent in Oil-Based Drilling Fluid

Table 1

Rheological behaviors of oil-based drilling fluid under different HBPA concentrations (before and after the thermal aging tests at 180°C for 16 h).

HBPA concentration (wt%)	AV (MPa·s)		PV (MPa·s)		YP (Pa)		GEL (Pa/Pa)		ES (V)
	Before	After	Before	After	Before	After	Before	After	Before	After
0	53	60	39	44	14	16	4/8	4/9	1255	1345
0.5	53	61	39	45	14	16	4/9	5/10	1258	1355
1	54	61	40	45	14	16	4/9	5/10	1262	1364
2	54	63	41	46	13	17	4/10	5/11	1268	1372
3	55	64	42	47	13	17	4/10	5/11	1275	1380