Three vertical appraisal wells in Changbei, Shaanxi Provice, P.R. China were drilled in 2008. It was decided to convert them to producers through hydraulic fracturing. To effectively fracture the wells, Changbei team faced several challenges:

  • Our partner prefers the use of local service company to control cost.

  • Within Shell, there experience in using local products to ensure the success of the operation.

  • ShellChina did not have local specialists in conducting quality fracturing jobs without external technical support.

  • Hydraulic fracturing was not part of the original well design consideration. This imposed some challenging fracture design constraintslimiting the flexibility of selecting the optimum engineering parameters for the treatments.

A task force consisting of ShellChina subsurface and well service personnel, Shell Global Stimulation Delivery Team (SGDT) members, and regional stimulation focal point had been established. The team had quickly resolved most of the issues for the operations. The key activities are:

  • Established working structure among ShellChina, SGDT, Shell regional expert, PetroChina employees, and local service companies.

  • Test local fracturing fluid systems and work with the provider to establish a QA/QC procedure.

  • Optimized design and execution based on the well and reservoir conditions.

  • Development and implementation of a comprehensive quality program. This included

    • Strict onsite HSSE practices and QA/QC and a close working relationship with local service company.

    • Rigorous lab testing of all fluids and materials.

    • Inspection on local service company's equipment to meet global HSSE and technical standards.

The first well (Well A) encountered initial flow back difficulty due equipment error, but eventually came back as designed. The operation on the second well (Well B) is a full success. This well is among the best vertical wells hydraulically fractured in the block.

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