Schlumberger Technology Corporation

Denis Vladimirovich Klemin

Vyacheslav Pimenov

Denis Vladimirovich Rudenko

Method for preheating an oil reservoir comprises injecting saturated or superheated steam at an initial injection pressure into a tubing placed inside a well drilled in the oil reservoir. Steam temperature at an outlet of the tubing is measured and a heat flow from the well to the oil reservoir is calculated. An optimal steam injection rate when steam quality of the injected steam at the tubing outlet becomes greater than zero, is calculated, the optimal steam injection rate ensuring compensation of the heat flow from the well to the oil reservoir with the heat of steam condensation. A steam injection rate is decreased to the calculated optimal steam injection rate value by decreasing the initial injection pressure providing constant temperature at the outlet of the tubing.

Method for preheating an oil-saturated formation

Method comprises measuring temperature along an injection well, measuring a steam quality and an injection rate at an inlet of the injection well and estimating a pressure distribution profile. Then a steam injection profile is estimated using the obtained pressure distribution profile and the measured injection rate combined with a one-dimensional injection well model for pressure losses in the well and heat exchange between an injection well tubing and an annulus. The obtained steam injection profile is used as an input parameter for a set of two-dimensional cross-sectional analytical SAGD models. The models are based on energy conservation law and take into account reservoir and overburden formation properties, heat losses into the reservoir and overburden formation impact on production parameters and SAGD characteristics. SAGD process characteristics are estimated from the set of two-dimensional cross-sectional analytical SAGD models.

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Moscow, Russia

Denis Vladimirovich Klemin