Optimized Stand-Alone Screen Design for the 'J' Field, Malaysia

Abstract

Gravel pack and stand-alone screens (SASs) are the two most commonly used sand-control methods for openhole (OH) well completions in unconsolidated formations. When comparing the two methods, gravel pack is considered the more robust for sand control and is expected to have a longer service life than SAS in similar reservoir and operational conditions. However, gravel pack costs more per foot than SAS, which limits its use to poorer-quality sands in projects with acceptable economics. The industry has developed accepted criteria for selecting these sand-control methods, and this documentation provides guidelines as to when SAS should be sufficient and when gravel pack is more appropriate, depending on sand quality, which is based on particle-size distribution (PSD) of formation sand samples.Unfortunately, many small oilfields with poor quality unconsolidated formations cannot be developed economically using gravel pack. SAS is the next best alternative, and often, the only option to bring those small oilfields online. The 'J' Field in Malaysia is an example of a small oilfield with marginal economics that was developed successfully using SAS completions despite the fact that the sand quality called for gravel packing. This paper discusses the methodology used in selection and sizing of the SAS design for the 'J' Field.The methodology involves two major processes: 1) review of PSD information for initial screen micron rating selection, and 2), retention-plugging testing of wire-wrapped screen (WWS) and mesh screens for screen-type selection and screen micron rating optimization. Using this methodology, the operator and service company were able to design a completion strategy for eleven (11) wells that fulfilled the economic needs of the development project while resolving the sand-control needs.

Sand Control Methods

“…The overall statement was that the combination of any of tested screen and gravel pack provides the best sand control. The value of proposed criterion has been proved in selection of sand control systems for small oilfields with poor quality unconsolidated formations (Regulacion et al 2011). The selection is primary based on economics, because gravel packs are too expensive for such fields.…”