The field of numerical reservoir
simulation has become one of the fastest growing bodies of knowledge over the
past two decades, because of the strong demand for reliable predictions of
reservoir performance. The tremendous progress in electronic computing
hardware, and the significant improvement in methods of numerical analysis were
two important factors in the achievements made in numerical models of
reservoirs such models made important contributions to the enhanced oil
Reservoir models are used for
understanding and prediction of reservoir performance.
History matching is one of the most
important activities during the development and management of petroleum
reservoirs. Matched models are fundamental to ensure reliable future forecasts,
and give an idea of the level of understanding of the geological and reservoir
models. Petroleum reservoirs are very complex and there are great difficulties
involved in building correct reservoir models. Depending on this level of
knowledge, available production data, and complexity of a reservoir, this
activity may be very time consuming. In order to achieve matched models,
sometimes little changes can be made on the geological and reservoir models,
mainly in those attributes with higher uncertainty, for example, relative
permeability curves, its distribution through the reservoir, and other
parameters with few samples.
One of the objectives of this work
is to perform history matching on the Zh86 Block in Zhaozhouqiao oil field using
Schlumberger’s simulation software Petrel. The history match will be done based
on trial and error by modifying some reservoir properties, end point scaling and by modeling and including the
aquifer support into the system. The best history match was achieved by modifying
the critical water saturation (SWCR) in the system, modeling an aquifer support
using Carter Tracy Aquifer model and by modifying the horizontal and vertical
Permeabilities of the model. After the history match is achieved two prediction
strategies are developed and compared, where we did forward modeling to build
some confidence level in the reservoir model. Production indexes; water cut,
water production, oil production and oil rate of wells and the field as a whole
were forecasted. Results of the indexes were presented against time and
analyzed. The results portrayed that Zh86 Block in Zhaozhouqiao oil field is
still very promising in terms of production.
An Uncertainty and sensitivity
assessment was done on the reservoir model to analyze the impact certain
reservoir properties have on the volume calculations and simulation results in
the Zh86 Block reservoir model. The impact of uncertainty in our Sw and contact
positions on volume calculations in this model can be seen.
The impact of the grid resolution
in placing horizontal wells was also studied, a synthetic model of the Zh86
Block was built selecting the varying grid resolutions both laterally and
vertically, and then properties were upscaled to the models and a well-placed
below an impermeable shale zone in each model to determine the optimum
location. Using a model with a fine grid resolution enables you to place the
well in the best position in the reservoir model.
matching, Reservoir performance, Production Prediction and Forecasting.