SCALING PLUG PROBLEMS OBSERVED IN SOME CERRO PRIETO GEOTHERMAL PRODUCTION WELLS

Abstract

Accelerate scaling problems in some Latina-Calpine wells in Cerro Prieto geothermal field have been causing high steam decline productions in short time. Well 614 began to shows high steam production decreasing, only seven months after was connected to the power plant system, therefore were done many operation on this well, like orifices plate diameter changes for try to remove the scaling plug formed inside of it. However, it was not possible, because was necessary to repair it, cleaning production casing and open hole production interval, the production recovered after the workover was around 90 % of the original production conditions. During second well 614 production period, was observed accelerate scaling plug, due to was necessary to repair it again , the production recovered after this second workover was around 90 % of the original production conditions.

Other fast scaling obstruction events were found in well 629, it started the production period in September 97, five months later began to shows a high decline steam production, loosing around 50 % its capacity, some action conduced to close and open the well, finally the well could removed the scaling plug, reaching similar production level of the original production.

This paper shows five examples about scaling plug problems in wells drilled on the Cerro Prieto reservoir, usually the scaling plug problems are associated to zones where produce more steam flow rates than water flow rate.
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