How do you optimize well spacing and completion design for tight oil reservoirs?

1 Formation evaluation data

Formation evaluation data are essential for characterizing the reservoir properties, such as porosity, permeability, fluid saturation, pressure, and stress. These data can be obtained from various sources, such as core analysis, well logs, well tests, and seismic surveys. Formation evaluation data can help you identify the sweet spots, or the zones with the highest potential for oil production, and the heterogeneity, or the variation of reservoir properties within and between layers. These information can help you design the optimal well placement, orientation, and length to maximize the contact with the sweet spots and avoid the low-quality zones.

2 Hydraulic fracturing design

Hydraulic fracturing is a process of creating and propagating cracks in the reservoir rock by injecting fluid under high pressure. Hydraulic fracturing can enhance the permeability and connectivity of the tight oil reservoir, allowing more oil to flow to the wellbore. However, hydraulic fracturing also requires careful design to optimize the fracture geometry, spacing, orientation, length, height, conductivity, and fluid volume. These parameters can affect the fracture interference, or the interaction between adjacent fractures, which can either enhance or reduce the oil production. Formation evaluation data can help you calibrate and validate the hydraulic fracturing models and optimize the fracture design based on the reservoir properties and stress conditions.

3 Well spacing optimization

Well spacing is the distance between the horizontal wells in a tight oil reservoir. Well spacing can affect the drainage area, or the volume of reservoir that each well can access, and the interference, or the interaction between adjacent wells. Well spacing can have a trade-off between maximizing the initial production rate and minimizing the decline rate. If the well spacing is too large, some of the reservoir may be left undrained, resulting in lower recovery factor and higher development cost. If the well spacing is too small, the wells may interfere with each other, resulting in lower production rate and higher operational cost. Formation evaluation data can help you estimate the drainage area and interference of each well and optimize the well spacing based on the reservoir characteristics and economic criteria.

4 Completion optimization

Completion is the process of preparing the well for production after drilling and fracturing. Completion can include various operations, such as perforating, installing artificial lift, stimulating, and controlling the flow rate. Completion can affect the productivity, efficiency, and durability of the well. Completion optimization is the process of selecting and applying the best completion techniques and technologies for each well based on the reservoir conditions and production objectives. Formation evaluation data can help you evaluate the completion performance and optimize the completion parameters, such as perforation density, artificial lift type, stimulation fluid, and flow rate control.

5 Monitoring and evaluation

Monitoring and evaluation are the processes of collecting and analyzing data during and after the production of tight oil reservoirs. Monitoring and evaluation can help you track the reservoir behavior, such as pressure, temperature, fluid composition, and fracture propagation, and the well performance, such as production rate, decline rate, and recovery factor. Monitoring and evaluation can also help you identify and diagnose the problems, such as water breakthrough, gas coning, fracture closure, and wellbore damage, that may affect the production efficiency and profitability. Monitoring and evaluation can provide feedback and insights for improving the well spacing and completion design for future wells or for implementing remedial actions for existing wells. Formation evaluation data can help you design and implement the monitoring and evaluation methods and tools, such as pressure transient analysis, tracer tests, microseismic monitoring, and production logging.