HORIZONTAL UNDERBALANCED DRILLING IN NORTHEAST BRAZIL: A FIELD CASE HISTORY SPE 69490
Language: Inglés Series: Cunha, J.C ; Publication details: Dallas, Texas Society of Petroleum Engineers 2001Subject(s): Online resources: Summary: This 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.| Current library | Status | Barcode | |
|---|---|---|---|
| Biblioteca virtual | Not for loan | 200003056 |
This 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.
