000			02270nmc a2200265 4500
005			20260520005605.0
008			260224s2001 xxu ing
041			_aInglés
245	0	0	_aHORIZONTAL UNDERBALANCED DRILLING IN NORTHEAST BRAZIL: A FIELD CASE HISTORY _bSPE 69490
260			_aDallas, Texas _bSociety of Petroleum Engineers _c2001
270			_a12/09/06 ; 09/05/2003
520			_aThis paper describes aspects related to planning and execution of four horizontal wells drilled underbalanced in the Estreito Field. This field is located in Brazil’s Northeast Region (Fig. 1) and has its production zones depleted. It was discovered in 1982 and today it has more than 700 wells. Estreito field has its producing reservoir very shallow and the formation is very unconsolidated, these poses especial challenge to achieve and maintain underbalanced condition at all times during the drilling operation, requiring especial care not only during the planning, but also for the execution of the well operations. In order to achieve the required bottomhole pressure (ECD = 6.9 ppg) nitrogen was injected into the water base drilling fluid, through the standpipe. Since the wells were horizontal, it was required the use of electromagnetic MWD/GR once the regular MWD would not work properly on a gasified fluid. In these wells it was successfully tested a compact vertical gas-liquid separator with an automated control system and data acquisition system developed by Petrobras. A skimmer was used for the solids-drilling fluid-oil separation.
942			_cCONGTP
100	1		_aCunha, J.C. _92476
100	1		_aRosa, Fábio Severo _96146
100	1		_aSantos, Hélio _96147
111	2		_aLatin American and Caribbean Petroleum Engineering Conference (7th : 2001 mar. 25-28 : Buenos Aires, Argentina) _95738
650		0	_aPerforación bajo balance _92538
700	1		_aRosa, Fábio Severo _96146
700	1		_aSantos, Hélio _96147
711	2		_aLatin American and Caribbean Petroleum Engineering Conference (7th : 2001 mar. 25-28 : Buenos Aires, Argentina) _95738
800	1		_aCunha, J.C. _92476
999			_c131002 _d131002
856			_uhttps://biblioteca.iapg.org.ar/ArchivosAdjuntos/LACPEC2001/Spe69490.pdf