The work completed was a comprehensive look into a mature gas field's intervention and production history to identify underachievement, redevelop the field management plan and implement successful remediation operations. The identification and characterization of skin was initially completed with physical inspection and slickline techniques. The decline curve analysis applied adapts to erratic declines from changing wellbore conditions, unreliable, or incomplete histories and provided accurate production forecasts. Pumping and coiled tubing techniques were used in the remediation work. In 2003 an Association was formed to manage a mature Romanian gas field producing since 1970. Production skin was evident and in 2010 the first well failed due to halite formation; consequently, liquid and solid sampling tools were deployed within suspect wellbores. The damage was characterized (halite, calcite and water blockage), novel decline curve analyses detected underperformance by integrating cumulative production histories. Twenty-two wells from one zone were initially assessed. All were damaged with some showing physical evidence of scale or salt, and a seven well pilot intervention campaign resulted in 38% peak incremental production. The outstanding results matched decline curve expectations and led to a full-field study, a campaign to intervene over half of the field based on that study, and possible expansion to all remaining wells in subsequent years. Technically, the innovative decline curve analysis proved crucial to discovering opportunities. Operationally, the optimized intervention procedures introduced were new to the basin and have been adopted by the Association partners in other assets. A major limit on ultimate recovery from depleted hydrocarbon reservoirs is declining well productivity. Salt formation, scale deposition, and water loading restrict flow: reducing production rates and increasing operating costs due to remedial interventions. Therefore, economical skin management is an essential tool for extending field life, increasing profitability, and improving recovery factors from aging assets. Impressive results led to a strategic shift in local field production management and the techniques are useful worldwide in similar fields.

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From the summer of 2014 to the summer of 2015, global oil prices declined by nearly 60%. The initial impact of this decline on unconventional assets was to reduce or stop drilling and completion activity, but the lower oil price also had a significant impact on cash flow from existing wells. Operators were able to achieve some reduction in operating expenses through contract renegotiations with suppliers, but cash flow margins from sales of oil and gas from production operations were severely impacted. In fields with higher operating expenses due to corrosive environments, the need to manage costs became even more critical. For example, in onshore fields with highly corrosive reservoir fluids, production chemicals can account for more than 40% of monthly operational expenses. Reducing chemical spend can therefore seem like an easy way to reduce lifting costs. However, a reduction in treatment volume can lead to mechanical integrity issues that are more costly to remediate than to prevent, therefore requiring a strategy to balance cost reduction and mechanical integrity preservation.A cost-conscious corrosion management strategy was developed and implemented for an onshore, sour-bacteria-laden oil from a shale oil development in south Texas. The strategy addressed treatment cost per barrel produced, the effectiveness of chemical formulations, metallurgies of downhole and surface facility components, and the cost of remediation. This full-spectrum corrosion management approach had a positive financial impact across the field.Key performance indicators were defined and tracked, and a workflow was implemented to manage the large amounts of data from wells in the field. A lifecycle data management system was employed to not only capture failures, but also facilitate root cause analysis. This afforded the opportunity to design-out repeat failure mechanisms, for example by changing downhole metallurgies. This workflow supported the on-time optimization of chemical pumping rates, which reduced operating costs without ceding equipment integrity. This workflow reduced time spent toiling over corrosion management, thus saving on engineering resources.Despite a challenging economic environment, corrosion management must be maintained in operational budgets. The example of the successful cost-conscious methodology used in the south Texas field shows that even dramatically reduced budgets can still support the safe, environmentally sustainable operation of an oilfield asset.

The work completed was a comprehensive approach of understanding and treating formation damage to further redevelop a mature asset through successful remediation operations. The identification of skin was completed with slickline techniques and reservoir and production flow profile monitoring. Primary formation damage mechanisms were naturally occurring scales in the near wellbore, damage caused by water blockages and workover fluids. Redesigned completion fluids, acid pumping and innovative coiled tubing tools were used in the remediation works which were all firsts in the basin. A modified decline curve analysis technique was used to economically justify treatment of nearly all wells in the field and led to substantial production increases.In 2003, an Association was formed to manage a mature Romanian gas field producing since 1970. Production skin was evident and in 2010 a well failed due to halite formation. Consequently, liquid and solid sampling tools were deployed within suspect wellbores. In 2010, a new workover fluid formulation was introduced but despite improvements formation damage was still induced. From 2010 to 2013, there had been an increased focus on understanding and treating calcite, halite and water block damages to boost field-wide productivity.Formation damage was observed as being both naturally occurring and induced in the field. An initial assessment and pilot treatment of 10% of the wells led to a near 40% incremental gain in those wells. After which, the campaigns were further expanded to over 75% of the field. Technically, the investigation into formation damage changed the development plan for the field going forward. Operationally, the intervention procedures introduced were new to the basin and have been adopted by the Association's partners in other assets.A major limit on ultimate recovery from depleted hydrocarbon reservoirs is declining well productivity. Salt formation, scale deposition, and water blockage restricts flow, reducing production rates and ultimate recovery of reserves. Therefore, economic formation damage management is an essential tool for extending field life, increasing profitability, and improving recovery of aging assets. Impressive results led to a strategic shift in local field production management and the techniques are useful worldwide in similar fields.