Abstract Field X in India has been developed as an onshore field wherein wells are drilled in shallow reservoir. There are approximately 110 oil producers and 60 water injectors in this field. To mitigate sand production, wells have been completed with standalone screens (including conventional, SSD & ICD). Crude of the reservoir is high in wax content with pour point at 50 C.
This paper highlights a case study on one of the oil producer X-A which was drilled & completed as 4-1/2” standalone screen completions to ensure selective production from various sands. Post completion, in all the subsequent rigless interventions conducted in the well X-A, an obstruction was observed against one of the Screen SSD. Initially a scale build up or a sand bridge was suspected at the obstruction depth, but well bore clean out with coiled tubing intervention failed to clear it off and pass through. Also, communication was suspected between tubing & tubing-production casing annulus. In view of above, the well was kept shut-in for more than a year.
This well, therefore became a critical case wherein application of Downhole Video Camera detected the potential leak in the tubing above the production packer and buckling of lower completion. Further, the Production Logging Survey confirmed the leak in the tubing. Based on the above field observations a CT conveyed Taper milling was conducted to clear off the obstruction post which work-over was conducted for upper completion.
This paper details the collaborative approach of diagnostic and troubleshooting interventions planned in the well X-A, challenges involved in the same and lessons learnt during the whole operation, which finally helped in bringing the well online successfully and affordably, avoiding numerous time and money consuming interventions which could have been carried out in absence of detailed root cause analysis of the problem.
Introduction
Well X-A is a deviated oil producer in field X. Post completion of the well, during attempts to flow back the well, an obstruction was observed around one of the screen SSDs which prevented any well intervention to bring the lower zones on production. Several conventional attempts were made by slickline & coiled tubing to clear the obstruction but all interventions were in vain and no success was observed. In addition to failure to clear the obstruction, these conventional methods also failed to provide clear indication regarding the cause & type of obstruction. Further sections of the paper highlight the well investigation with Downhole Video Camera technology and then clearance of obstruction with Coiled Tubing conveyed Thru-Tubing Tapered Mill.