Abstract

Sand problem and heavy oil has been the major constraint in producing oil in Sesanip Field Tarakan. The field has unconsolidated sand reservoir with grain size D50 of 200 – 300 µm and oil gravity of 18-22 deg API. Under those conditions, Progressive Cavity Pump (PCP) performance and lifetime has been a major constraint in producing the field. Five production scenario been implemented to acquire the most optimum lifting method.

Production scenario was divided into two phases. First phase was implementing PCP without sand control. This production scenario was used as a baseline for improvement. Second phase of the production scenario was to add sand control into the production system. Improvement between the two production scenario will be assessed using several criteria; lifetime, cumulative production, economic analysis. In the first phase, three production scenarios with PCP below perforation, PCP above perforation, and PCP with controlled production rate were implemented. Whereas in the second phase, results from downhole configuration of screen installed to pump intake, and installation of screen using seal-bore packer were compared with first phase results.

Comparison between five producing scenario were analyzed according to the criteria determined. Based on the first phase results, excessive sand production was evident when producing in optimum rate. In order to minimize sand production, production rate must be limited and therefore sacrificing artificial lift potential. Second phase gave two different results. PCP installation with sand screen installed to pump intake gave the lowest cumulative production, lowest revenue, and longest pay out time. Although sand screen was used, the lack of sealing above screen meant that sand was allowed to pile up in the annulus and eventually restricting influx. PCP with sand screen installation using seal-bore packer delivers optimum trade-off between lifetime, cumulative production and economic values. By applying this production method, sand production from the reservoir will naturally form sand-pack between perforation and sand screen. Although this sand-pack would decrease productivity index, but it compensates with higher lifetime. Based on recent well service activity, no sand pile was present inside screen or above seal-bore packer.

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