Is High Viscosity a Requirement for Fracturing Fluids?

Uniformly distributing proppant inside fractures with low damage on fracture conductivity is the most important index of successful fracturing fluids. However, due to very low proppant suspension capacity of slickwater and friction reducers fracturing fluids and longer fracture closure time in nano & pico darcies formations, proppants settles quickly and accumulates near wellbore resulting in worse-than-expected well performance, as the fracture full capacity is not open and contributing to production. Traditionally, cross-linked polymer fluid systems are capable to suspend and transport high loading of proppants into a hydraulically generated fracture. Nevertheless, amount of unbroken cross-linked polymers is usually left in fractures causing damage to fracture proppant conductivity, depending on polymer loading. To mitigate these challenges, a low viscosity-engineered-fluid with excellent proppantcarrying capacity and suspension-in excess of 30 hours at static formation temperature conditions - has been designed, enhancing proppant placement and distribution within developed fractures, with a 98% plus retained conductivity. In this work experimental and numerical tests are presented together with the path followed in developing a network of packed structures from polymer associations providing low viscosity and maximum proppant suspension. Challenges encountered during field injection with friction are discussed together with the problem understanding characterized via extensive friction loop tests. Suspension tests performed with up to 8-10 PPA of proppant concentration at temperature conditions are shared, together with slot tests performed. Physics-based model results from a 3D Discrete Fracture Network simulator that computes viscosity, and elastic parameters based on shear rate, allows to estimate pressure losses along the flow path from surface lines, tubular goods, perforations, and fracture. This work will demonstrate the advanced capabilities and performance of the engineered fluid over conventional fracturing fluids and its benefits. Additionally, this paper will present field injection pressure analysis performed during the development of this fluid, together with a field case including production results after 8 months of treatment. The field case production decline observed after fracture treatment demonstrates the value of this system in sustaining well production and adding additional reserves.

The Archaeology of the Arabian Peninsula 2

The volume presents the proceedings of the second international workshop on the Archaeology of the Arabian Peninsula. Its subtitle, 'Connecting the evidence', portrayed our striving for investigating relationships and connections between different regions, materials and themes of research. The nine contributions straddle the entire expanse of the Peninsula and beyond, in order to counter the present divide in different academic disciplines. The chronological focus spans from the Pre Pottery Neolithic, the Bronze and Iron Ages down to the Islamic Middle Ages. The analyzed themes range from funerary to cultic landscapes, oasis formation and role of metallurgy for desert dwellers in state-of-the-art interdisciplinary perspectives and field case studies.

Geomechanical model and sanding onset assessment: A field case study in Vietnam

Sand production is a key issue when selecting and applying completion solutions like open holes, screens or perforated liners. This problem can be seen in several types of reservoirs such as weakly consolidated and non-consolidated carbonates. The paper presents a method to model wellbore failures for sanding prediction. Our study shows that the potential sand risk in this field is defined by the rock strength rather than the in-situ stress. If the rock is sufficiently competent, the potential of sand production is negligible, and the development wells can be completed conventionally without any downhole sand control for the reservoir pressure above 1,280 psi and the maximum drawdown pressure of 2,380 psi.

Iterative modeling is as a tool for selecting a geological basis for hydrodynamic modeling and development design

The usual method for constructing a digital model of a field is based on hydrodynamic modeling using the basic implementation of a geological model, usually requires additional adjustments to the initial data, and as a result, leads to a wide range of uncertainties in assessing the predicted technological indicators of field development. The PK1 reservoir of a gas condensate field case study discuss-es the method of iterative modeling, which makes it possible to comprehensively approach the assessment of possible uncertainties.

Comparison of various lithology volumes building methods: a case study of the Bejil field

The Bejil field case study shows the comparison of 3D lithology volumes built by various methods, applied world-wide. A net-reservoir volume is an important and integral part of 3D geological models, which determines the oilnet pay part of the reservoir. The quality of the geological model directly affects the concept of the studied geological environment. Two lithology volume options are considered in detail. The first method, which is more popular in domestic applications, involves building a lithology volume directly based on logging data interpretations. The second method, which is more widespread internationally, involves building a volume of facies environments followed by distributing various lithotypes in a reservoir taking into account the facies structural features. As a result, we made allowance for the tasks and geological features of the field and chose the best modeling method.

Comparison of Various Discretization Schemes for Simulation of Large Field Case Reservoirs Using Unstructured Grids

Solving the equations governing multiphase flow in geological formations involves the generation of a mesh that faithfully represents the structure of the porous medium. This challenging mesh generation task can be greatly simplified by the use of unstructured (tetrahedral) grids that conform to the complex geometric features present in the subsurface. However, running a million-cell simulation problem using an unstructured grid on a real, faulted field case remains a challenge for two main reasons. First, the workflow typically used to construct and run the simulation problems has been developed for structured grids and needs to be adapted to the unstructured case. Second, the use of unstructured grids that do not satisfy the K-orthogonality property may require advanced numerical schemes that preserve the accuracy of the results and reduce potential grid orientation effects. These two challenges are at the center of the present paper. We describe in detail the steps of our workflow to prepare and run a large-scale unstructured simulation of a real field case with faults. We perform the simulation using four different discretization schemes, including the cell-centered Two-Point and Multi-Point Flux Approximation (respectively, TPFA and MPFA) schemes, the cell- and vertex-centered Vertex Approximate Gradient (VAG) scheme, and the cell- and face-centered hybrid Mimetic Finite Difference (MFD) scheme. We compare the results in terms of accuracy, robustness, and computational cost to determine which scheme offers the best compromise for the test case considered here.

Laboratory Performance and Field Case Study of Asphalt Mixture with Sasobit Treated Aramid Fiber as Modifier

The use of fiber in asphalt mixtures can improve the mixture’s tensile strength and increase its cracking resistance, but the clumping of fiber in the mixture can weaken the improvement effect. The aim of this research is to assess the properties of Sasobit treated aramid fiber modified asphalt mixture and to validate the field case study. The rutting and stripping resistance of the fiber-modified mixture was identified with the Hamburg wheel tracking device. The low-temperature cracking characteristics of the asphalt mixture were quantified with the disk-shaped compact tension test. Moreover, the dynamic modulus test was adopted to reflect the response of the mixture to different loads and frequencies. The creep slope and stripping slope decreased by 67%, and the number of passes to stripping point and fail point increased by more than 250% after fiber modification. The fracture energy, peak load, and maximum crack mouth opening displacement (CMOD) of the mixture increased more than 10% after fiber modification. The dynamic modulus, rutting parameter, and fatigue parameter of the mixture were improved after fiber modification. The fiber in the mixture improved the stiffness of the mixture at high temperatures. The tensile strength improvement at low temperatures promoted the cracking resistance of the mixture. The cracking number in the fiber modified asphalt pavement was less than that in the control asphalt pavement. Thus, fiber modification could significantly restrict the propagation of cracking in the asphalt mixture. The implementation of fiber in the project can provide experience for future fiber application in asphalt pavement.