High Definition Modeling for Complex Multilateral Well with Smart Completions
Authors: AlQahtani Ghazi D. , Shaker Wisam , Ismail Menhal , Tareq Shaalan , Jibran Ayub , Saud Hoti 
Published: May 2020

Multilateral wells may vary in the number of laterals from two to even more than ten laterals. To control production on a lateral level, advance completion equipment, such as Inflow Control Valves (ICVs) and dual ported Permanent Down-hole Monitoring Systems (PDHMS) for real-time pressure measurements, are installed in the motherbore against each lateral to regulate reservoir fluids into the production tubing of the well from individual or collective set of laterals. Multilateral wells equipped with advance completion tools become complex wells (hereinafter called the "complex wells") in reservoir engineering. Recent complex wells involve multiple designs and architecture for which the reservoir exposure for laterals sums can be thousands of meters.

A new generation of smart multilateral well completions are Manara type wells where the laterals are divided into a number of segments or compartments using oil swell packers and Manara stations are placed against each segment for quantifying liquid rate, water cut and real-time reservoir pressure measurements. Each station is equipped with electrical control valve for controlling unwanted fluid production at a segment level. In this work, a new workflow is established to model and history match Manara well with complex modeling features using the GigaPOWERS (GP) simulator and a compositional full field model. The established segment level history matching workflow includes four important milestones to achieve. The first is advance well completion design at which the physical well completion details are translated and converted into a grid based completion details with the help of pre-processing tools. The second step covers the generation of three complex well-related input files for the GP simulator. The third step is the process of validating high frequency performance data including flow rate, choke size and pressure for the complex well stations. The last step involves conducting the history matching exercise on a segment level for every individual station to achieve the final history match model.

The conventional history match procedure includes generally three levels to match; field, group and well. In this workflow, station level match is done for the first time with a full field compositional model with a size of more than 61 million grid cells. The high definition history match is achieved at segment level for six stations that constitute a trilateral well with high frequency performance data. Complex well modeling in GP includes pressure drop calculations for several components. The pressure drops are related to friction, gravity, acceleration and advanced tools (i.e. ICV).

Modeling a complex well involves several pre- and post-simulation environment features at the segment level that should work in complete consistency. The achieved outcome enables a business impact evaluation for an accurate value proposition for complex well incremental rates, cash flow streams and sensitivity prediction cases.