With current demand for gas at historic peak, any decrease in production due to deposits of scale within tubing is the most troublesome for any E&P company. Statistically 28% of time it is the scale in well that hinders producing it at optimum rate. "Carbonate" and "Sulfate" scales are most common of mineral scales that form in wells. Carbonate scales are generally tackled by wellbore cleanout with acid or by using scale inhibitors to slowdown scale deposition process but none of these solutions solve the problem on permanent basis. Sulfates scales are generally very hard to remove through acid job and usually chemical chelants are used to control sulfate scales.The major production enhancement challenge faced in well 'X' was to permanently mitigate severe scale build up issue in tubing for optimum production performance. This paper presents how these challenges were faced and overcome by using ClearWELL * unit, resulting in stable and continuous production.A scale study was conducted by OMV laboratory in Vienna to identify the scale build up mechanism and solutions for its mitigation. The study confirmed that minor pressure decrease at formation temperature promoted water transfer into the gas phase, if water rate is low compared to gas rate, this can result in complete evaporation and formation of precipitate leading to scale build up (mainly calcite). To reinstate production, repeated wellbore cleanouts with coiled tubing using diluted HCl (7.50%) were thought to be the temporary solution in fighting CaCO 3 scales.ClearWELL unit was commissioned at well 'X' x-mas tree, which is currently under pilot testing. It is an electromagnetic device which continuously generates electronic dipole that induces a randomly varying high frequency electric field throughout the entire piping system. The electric field * ClearWELL is an electromagnetic device. generated by device forces homogeneous crystal formation in suspension rather than on metal surfaces. Scale crystallizes in suspension and is carried away with gas water mixture.During last 5 months of its pilot testing, results achieved so far are promising. Stable and no lost production added a reasonable value to the producing asset and saved huge revenue loss to the company.

The objective of writing this success story is to demonstrate how technology, in particular low cost solutions, are key to economically sustain and secure production from mature fields. Tubing Patch technology has been successfully utilized in Pakistan for the first time to restore the well integrity and saved huge CAPEX by avoiding expensive rig workover. Tubing-Annulus pressure suddenly increased in one of water disposal well (WDW). Annulus pressure varied directly with variations in Injection rates which were the clear evidence that tubing-annulus communication had been established and basic check ascertains that well had integrity issue. Being the only injector in area all production and processing of gas is majorly dependent on its injection reliability and integrity. After detailed in-house working it was decided to run diagnostic logging with spinner (quantitative) & temperature log (qualitative) to identify the leakage points precisely. All potential leakage paths (packer, tubing, tool joints) were considered while selecting the diagnostic techniques to have conclusive results. Based on diagnostic logging three leakage points were identified. Before proceeding for remedial measures to restore the well integrity, it was mandatory to check health of old carbon steel tubing string therefore it was planned to acquire corrosion log. Based on corrosion logging results, completion tubular was established in good condition which steered to install tubing patches best Techno-Economical solution across the leaks to restore well integrity instead of rig workover for re-completion. Consequently, three tubing patches, were successfully applied using wireline in water disposal well and integrity of well was restored. C-Annulus was pressure tested even after six months of installation and no pressure drop was observed during this interval.

Well ‘X’ was drilled in a gas condensate reservoir located in Kirthar fold belt with the primary target of P & R formations. During CIT of P formation in April 2012 the well was tested at 4.03 MMscfd gas, 1543 STB/day condensate & 1670 bbls/day water at a FWHP of 309 psi. Available production logging surveys with water & gas holdup tools were performed twice to identify the water producing zones; however the results were inconclusive as commonly used production logging tools are able to identify production contribution only across the perforated intervals and cannot detect behind casing communication and flow within reservoir. The well had been shut-in as plant was not ready for tie-in, so opportunity was taken to conduct HPT-SNL suite (in memory mode with slickline) in August 2013 which resulted not only in identifying the water producing zones but also confirmed hydrocarbon influx zones above perforated interval and flow behind casing from above perforated interval. HPT is a high precision temperature tool with resolution of 0.003oC and response time less than 1 second to capture any small flow, whereas SNL is spectral noise logging tool which can scan noise spectrum through multiple barriers for evaluation of any cross flow behind casing and leakages. Based on HPT-SNL results, water shut-off was performed which considerably reduced water production (from 1318 to 520 bbls/day), consequently reducing WGR (from 628 to 244 bbls/MMscf) with no change in gas rate whereas increase in condensate production was observed (from 330 to 855 STB/day). This paper describes the complete case study of diagnostic logging followed by remedial work to optimize the producing asset value.