Abstract
Field D is a massive oil-producing field, which consists of more than 15 blocks that have been developed since 1996. All types of completion methods, from openhole stand-alone screens and cased-hole circulating packs to frac packs, have been applied to help maximize field productivity while keeping sand issues to an acceptable level. However, some wells have begun to encounter sand issues, causing a drop in productivity and in some cases become shut-in because of sand accumulation in the tubing. Small fines (<40 micron) are particularly prominent in the produced sand based on samples collected. A field development revisiting campaign was launched to target new drainage points and recover attic oil using existing slots to sidetrack to the targeted zone and install a new downhole sand control completion. The preferred treatment method is an extension pack (EP) after considering reservoir characteristics, namely close proximity to a coal layer, low permeability, and small fines production, among others. These challenges were addressed by combining the oriented perforation design and optimal sand control completion system using a single-trip multizone system, enhanced single-trip multizone system, and a stack pack with a properly designed proppant pumping strategy using xanthan carrier fluid, a fines-control acid system, and 20/40-mesh ceramic proppant with a 10-gauge wire-wrapped screen. Numerous sand control software simulations were performed to achieve tip screenout (TSO) and a sufficient pack factor while addressing all of the wellbore conditions. For the first time in this field, conductivity enhancer material was applied by dry coating it to proppant on-the-fly with the goal of controlling fines migration through the proppant pack, thus increasing porosity and leading to long-term conductivity. The process design, execution, minifrac analysis, and post-job matching for the frac pack treatment are discussed, which lead to the wells producing sand-free at higher than expected reserves and flow rates. Best practices and lessons learned from this campaign can be further used for new upcoming campaigns.
