The primary aim of this study was to design a guideline in the form of a flow chart that can potentially be used in practice when optimal sand control methods and implementation of completion techniques are considered in sand producing wells. The flow chart could also serve as a tool during the decision-making process where sand control is deemed necessary. Distinct reservoir data and key parameters were incorporated into the designing of the flow chart. This paper predominantly focused on two of the most common techniques used currently in practice; sand screens and gravel pack.
A retrospective analytical review was carried out. A systematic search was undertaken to analyze sand control methodologies used in recent studies to ascertain key considerations undertaken when choosing gravel pack and/or sand screen. Studies selected were based on a predetermined set of inclusion and exclusion criteria. Recurrent pattern that existed when choice of a specific technique was identified; a list of criteria that was considered when selecting gravel pack and/or sand screen techniques was developed. Information and data obtained were then eventually integrated in stages into designing a concise flowchart.
List of criteria developed when contemplating sand control and completion methods were as follows, 1. Determine rock mechanics, 2. Study individual reservoir conditions, 3. Note lithological changes, 4. Obtain well data, 5. Characterize formation sand, 6. Select gravel size, 7. Select screen and size, 8. Select completion method and 9. Evaluate the potential cost and economical outcome. The development of flow chart then began with the categorisation of key information into four significant stages as follows, sand prediction, sand analysis, sand control and completion method. Looking at the step 1 to 9 of the list of criteria and the four phases of the flow chart together, a more structured and integrated thought process took place. When the sand analysis stage was referred to, criteria 1 to 5 were determined simultaneously. Then, the sand prediction stage was referred to in the flow chart where upon obtaining the sand production rate it could be determined if the sand produced was low/manageable. A choice to live with the sand produced is made if so. If the rate was high, then the rest of criteria 6 to 9 as per the list above were determined and advancement is made to the next stage flow chart according to the sections. Both, the criteria list and flow chart can be used in parallel as guidance when implementing respective techniques in an individual sand-producing well.