Applications of Oilfield Produced Formation Water for Fracturing Fluid

摘要

Oilfield produced formation water containing complex mixture of Dissolved Solid Compounds (DSC), including sodium, boron, chloride, magnesium, potassium, calcium, barium, iron and other salts is used in this research with the objective to develop stable and degradable cross linked fracturing fluid useful in both oil and gas producing reservoirs. As a result of recent increasing interest in horizontal drilling and hydraulic fracturing operations, large volume of produced and/or flow back water containing complex mixture of organic and inorganic compounds is generated in the oilfield during the oil and gas recovery operations. Independently owned to larger oil and gas producing operators manage the generated oilfield produced water by one or more of the strategies, which include disposal, re-use and recycling of the produced water. However, large water consumption and strict environmental disposal issues associated with hydraulic fracturing treatment, combined with industry growth, are generating a crucial need for developing a good viscosity and reliably stable cross linked fracturing fluid systems, useful for transporting propping agents into the fracturing zones at moderate to high temperature range using the generated oilfield produced water. Presented in this study are the results of rheology and residue analysis of fracturing fluid systems prepared with oilfield produced formation water from a broad spectrum of geologic basins. The rheology studies were conducted to measure viscosity under a nitrogen pressure of >400 Psi and temperature window of 210-260?F. The guar residue analysis test was performed with series of gel breakers at 185°F. The fluid systems presented provide proof of concept of the ability to crosslink and degrade cross linked fluids to below 100 cP at shear rate of 100/sec under the considered treating down hole conditions. Data presented provide guidance for the potential use of generated oilfield produced water as source water and/or blend water for water-shortage oil and gas producing operators and reducing the negative environmental impact.