A Successful Field Application of a New Chemical Treatment in a Fluid Blocked Well in Saudi Arabia

Abstract

A successful trial of the Gas Well Stimulant WS-1200 was recently completed on a gas well with high Condensate-Gas Ratio (CGR) and producing below the dew point to treat fluid blockage in Saudi Arabia. The treatment consisted of pumping from a surface 2 wt% active solution in common organic solvents that solubilizes and/or displaces the brine and condensate that are present in the near wellbore region of a fluid blocked well. After bullheading the treatment into the well, it was chased with two equivalents of nitrogen gas. The well was shut-in over night for the treatment to react and then the well was opened to flow and clean out. A test separator was connected to measure the flow at surface and compare the flow after the treatment. Several days were required after opening the well to back-produce the solvents and evaluate the well through the test separator until stabilization was acquired. The well was put back online and continued monitoring production for several months. Just prior to injection of the chemical treatment, the well was producing ~1.5 MMSCFD and ~275 BOD. Within five days of concluding the injection, the well was producing ~2.7 MMSCFD and ~1,000 BOD and in an increasing trend. The well was left in production with only the wellhead temperature (WHT) and wellhead pressure (WHP) being monitored on an ongoing basis. After three months of production, the well rate was again measured through a separator at similar conditions and found to be ~2.85 MMSCFD and ~1,152 BOD, a sustained improvement of 83% in gas production and a 313% improvement in oil production. In light of initial encouraging results, similar chemical treatments are planned in other sandstone reservoirs with similar problems.

Обзор Методов Повышения Компонентоотдачи При Разработках Газоконденсатных Месторождений

“…Был проведен ряд иссле дований, направленных на рассмотрение этого случая, которые показали, что переход от однофазного к многофазному течению около скважины приводит к образованию скопления конденсата. Согласно [38] когда конденсат образу ется вблизи ствола скважины, он создает три различные области подвижнос ти в резервуаре. В области, где давление жидкости еще выше давления точки росы, есть только одна газовая фаза.…”

Gas Condensate Banking: A Review of the Phenomenon, Accumulation, Mitigation Methods, and New Breakthrough

“…When the drawdown pressure hit below the dew point pressure, a small drop of condensate is formed and accumulated in the near wellbore region. As the accumulation occurs, the liquid saturation will also increase and the gas relative permeability is reduced, hence affecting the productivity (5,6).…”

Mitigation of the Effects of Condensate Banking: A Critical Review

“…They concluded that methanol/water mixtures were ineffective in removing condensate bank, while methanol and the mixture of isopropanol and methanol were effective in removing water from core samples. Alzate et al (2006) performed compatibility tests between reservoir fluids, alcohol, and inhibited diesel-based treatments, and they used formation cores from Cupiagua field. They found that compatibility is a function of the miscibility of alcohol in formation fluids, volumetric concentration of alcohol in the mixture, and the composition of the fluids.…”