A Case Study on Formation Evaluation of Horizontal Wells in the Tight Gas Nikanassin Group of the Western Canada Sedimentary Basin Using Drill Cuttings

SPE Latin American and Caribbean Petroleum Engineering Conference

2015

Self Cite

The objective of this paper is to present a methodology using drill cuttings for making estimates of porosity, permeability and compressibility as a function of confining pressures in tight formations.An easy to use correlation is developed by comparing results from experimental work including hysteresis at various combinations of overburden and pore pressures in vertical and horizontal core plugs, and permeabilities and porosities determined in the laboratory from drill cuttings. The work is important because of the presence of stress-dependent slot and/or microfracture porosities and permeabilities in tight formations that can affect significantly reservoir performance and forecasting.Recent work has shown that drill cuttings can be used quantitatively for complete petrophysical evaluation (for example determination of porosity, water saturation, pore throat aperture, Young Modulus, Poisson's ratio and brittleness index (Olusola and Aguilera, 2013; Ortega and Aguilera, 2014). The methods have been shown to be useful in those instances where cores and specialized well logs are scarce. Those methodologies are extended in this paper to quantitative evaluation of stress dependent properties.It is concluded that drill cuttings are important direct sources of information that can be used for developing estimates of stress-dependent properties particularly in those cases where cores and specialized logs are scarce or not available. The methodology and correlation are presented in detail as well as a practical application. Although the main and novel contribution is the development of an easy to use correlation for stress-dependent tight reservoirs using drill cuttings, the correlation can obviously be used if only plug data are available.

Section: Figure 14 -Compressibility Vs Net Confining Stress Applyingmentioning

confidence: 99%

Estimates of Stress Dependent Properties in Tight Reservoirs: Their Use with Drill Cuttings Data

Lopez

Piedrahita

SPE Latin American and Caribbean Petroleum Engineering Conference

2015

Self Cite

Multi-stage Hydraulic Fracturing Design In Horizontal Wells With The Use Of Drill Cuttings

Olusola

SPE Western North American and Rocky Mountain Joint Meeting

2014

Successful multi-stage hydraulic fracturing of horizontal wells requires a clear understanding of the in-situ stress profile. This implies knowledge of rock properties and pore pressure variations throughout the wellbore. These properties can be determined with a good level of certainty when complete data sets are available. In practice, however, data scarcity from horizontal wells is the rule rather than the exception. This has led in most instances to performing multi-stage hydraulic fracturing jobs in symmetric intervals throughout the horizontal well without regard to the optimum locations where hydraulic fractures should be initiated. This study shows how data extracted from drill cuttings collected in a horizontal well can be used for optimizing multi-stage hydraulic fracturing. The cuttings are used in the laboratory for measuring porosity and permeability and for estimating geomechanical properties (e.g. Young Modulus, Poisson's ratio, brittleness index). The data permit generating the in-situ stress profile and other geomechanical parameters in a hydraulic fracturing model. A comparison is made of two cases in a horizontal well of the Western Canada Sedimentary Basin (WCSB), where only a gamma ray log is available: In one case drill cuttings are used for estimating geomechanical properties to select fracture initiation zones; in the other case symmetric fracturing stages are selected without giving consideration to geomechanical properties. The conclusion is reached that the petrophysical and geomechanical knowledge acquired from the study of drill cuttings leads to better rates and improved ultimate recoveries.

Estimates of Stress-Dependent Properties in Tight Reservoirs: Their Use With Core and Drill-Cuttings Data

Lopez

Piedrahita

SPE Reservoir Evaluation &Amp; Engineering

2016

Summary The objective of this paper is to present a methodology with drill cuttings for making estimates of porosity, permeability, and compressibility as a function of confining pressures in tight formations. An easy-to-use stress-dependent permeability correlation is developed by comparing results from experimental work including hysteresis at various combinations of overburden and pore pressures in vertical and horizontal core plugs, and permeabilities determined in the laboratory from drill cuttings. On the other hand, stress-dependent porosity and compressibility correlations with respect to permeability as a function of net confining stress (NCS) are also introduced. The work is important because of the presence of stress-dependent slot and/or microfracture porosities and permeabilities in tight formations that can significantly affect reservoir performance and forecasting. Recent work has shown that drill cuttings can be used quantitatively for complete petrophysical evaluation and rock-mechanical-properties estimation (Olusola and Aguilera 2013; Ortega and Aguilera 2014). The methods have been shown to be useful in those instances in which cores and specialized well logs are scarce. Porosity and permeability values obtained from the aforementioned works are extended in this paper to quantitative evaluation of stress-dependent properties. It is concluded that drill cuttings are important direct sources of information that can be used for developing estimates of stress-dependent petrophysical properties particularly in those cases in which cores and specialized logs are scarce or not available. The methodology and stress-dependent-permeability, -porosity, and -compressibility correlations are presented in detail, as well as a practical application for the case of drill cuttings. Although the main and novel contribution is the development of easy-to-use correlations for stress-dependent tight reservoirs with drill cuttings, the correlations can obviously be used if only plug data are available.