Multi-Stage Hydraulic Fracturing Using High- Temperature Fracturing Fluids in the Deepest Offshore Well in China- Case Study of Lab Test and Field Execution

Abstract

Bohai Bay is one of the world's largest oil and gas fields, consisting of different reservoirs with multiple lithologies. BZ condensate oil and gas reservoir is discovered in recently past years. It is planning to develop this field in future years. This field are fractured buried hill condensate gas reservoir, buried deeply and it is not property researched. Several Wells drilled at early stage of the production schedule is not stable and economic value is not enough, so hydraulic fracturing technology is needed to realize the maximization of the production. Due to the well was deep with extremely high temperature and high pressure, the choice of the method of completion, fracturing process design and the realization of the project are challengeable. When the target well depth over 5000m with temperature over 195 °C, we usually use metal crosslinked fluids, particularly using CMHPG and crosslinked with Zirconate crosslinker designed for high temperature. This system delivers a great combination of benefits: availability, low cost, ease to use, high viscosity, and fluid recovery. BZ 9 well is the deepest offshore in China by far. We finish the multi-stage hydraulic fracturing using High-temperature fracturing fluids. We conduct DST test, production evaluation, DFIT Test, Hydraulic Fracture for BZ 9 well. Data analysis and caliber the production evaluation is also tried to do. The high temperature fracture fluid stability test, break test, surface tension test, core perm recovery test is shown is this article. At the same time, also show the well fracturing design idea and method of pump schedule, fracturing model result, DFIT and SRT process, understanding of the reservoir, display and analysis of fracturing plot, the full 3D GRID- ORIENTED HYFRAULIC FRACTURE STIMULATOR corrective, the analysis of the pressure plot, flowback and production, and further suggestions are put forward.