Lately, hydraulic Fracturing become common stimulation to improve economic by increase production and adding reserve through unconventional play from tight sand reservoir. The fracturing treatment creates highly conductive pathway to enhance production and well drainage which lead to add reserves. Mostly, Hydraulic Fracturing treatment had been performing in new development wells of infill wells. After successful resulted hydraulic fracturing campaign in new infill wells, there was a trial to perform hydraulic fracturing in existing well thru existing tubing completion. First well which was selected as first to perform remedial frac, thru tubing hydraulic fracturing is consider as a cheaper way to perform rigless hydraulic fracturing compare to hydraulic fracturing with rig. The main challenges during operational come from limitation of existing completion, several adjustment in design and operational should be perform to optimization during fracturing job. This paper presents the experience including fracturing limitation and fracturing design during performing first thru tubing hydraulic fracturing in tight sand reservoir in Offshore North West Java.

Several fields in South East Asia are suffering from excessive sand production due to clayey unstable reservoir rock. Sand production induces undesirable phenomena such as production loss due to sand accumulation in the well, damage of the pump and of the surface equipment, frequent well shut-in and heavy costs for cleanout jobs and pump changes. The operators are looking for an easy and cost-effective technique that could be deployed in the field, if possible rigless. In a previous paper5, a pilot treatment consisting of specific water-soluble polymer injection showed good results in terms of sand production reduction and preservation of well performances. The polymer adsorbs strongly on the reservoir rock, forming a continuous film on pore walls. The film has a consistency of thin sticky gel stabilizing the rock. Moreover, the polymeric film acts as Relative Permeability Modifiers (RPM) and thus maintain oil permeability while reducing water permeability. This RPM property enables the deployment by bullhead injection into the whole open interval. Field extension has been scheduled and similar treatments have been performed in 4 new wells. In the field, the polymer is injected by coiled tubing in each open interval selectively. The polymer is pushed in the formation by diesel/water postflush, which also re-saturates with oil the near-wellbore area and help production re-start. The feedback obtained so far can be listed as follows: No production loss occurred in all the treated wells.Sand-free production rate could be increased after the polymer treatmentSand production was totally stopped for a few months before coming back again after 4-12 months, at much lower rate than before.A re-treatment induced new period of sand-free production for several months. Such results confirm the sustainability of the polymer technology. The field methodology has been optimized. It opens new perspectives and could become a new sand control system in the toolbox of the profession.

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