The Fundamental of TCP Techniques

Strategies for prioritizing test cases plan test cases to reduce the cost of retrospective testing and to enhance a specific objective function. Test cases are prioritized as those most important test cases under certain conditions are made before the re-examination process. There are many strategies available in the literature that focus on achieving various pre-test testing objectives and thus reduce their cost. In addition, inspectors often select a few well-known strategies for prioritizing trial cases. The main reason behind the lack of guidelines for the selection of TCP strategies. Therefore, this part of the study introduces the novel approach to TCP strategic planning using the ambiguous concept to support the effective selection of experimental strategies to prioritize experimental cases. This function is an extension of the already selected selection schemes for the prioritization of probation cases.

Optimization of the Reservoir Pressure Maintenance System in a Low-Permeability Carbonate Field

The investigated field is located in the Solikamsk drawdown in the northeast of the Perm Territory. The oil content level of this field is composed of Tournaisian-Famennian, Radaevsky, Radaevian, and Tula formations. This article will analysis carbonate deposits from the Tula formation using the multiwell retrospective testing (MRT) technology. Currently, the development system has been already formed, and there is ongoing compaction drilling and targeted drawdown increase that is carried out at certain wells. A pressure support system has been formed. Before the surveys have been conducted, there was a trend in production decline, for reasons that are currently unknown. To identify the causes of production decline at the carbonate reservoir in the field, special technology was used to analysis production history data and bottom hole pressure - this technology is called multiwell retrospective testing (MRT). Four sections were selected for further analysis, MRT was able to reconstruct the reservoir pressure variations and production coefficient at the tested well, the influence of the offset wells on the tested wells has been evaluated, along with transmissibility at the cross-well interval and well-bore skin of the tested wells.

Waterflood Analysis in Compartmentalised Reservoir Using Multiwell Retrospective Testing and Tracers

The study field consists of four oil pays and is currently going through a waterflood trial. Due to a presence of high amplitude faulting it becomes crucially important to understand the geology of the field and reservoir connectivity prior to progressing the waterflood project. The results of the cross-well tracers have indication (some strong and some vague) of communication between a trial water injector and all oil producers in the same and adjacent compartment. Since the wells were equipped with permanent downhole pressure gauges it was possible to decipher the cross-well communication using the Multiwell Retrospective Testing (MRT) technique based on multiwell deconvolution algorithm (MDCV). The results of MRT study were showing no traceable communication between trial water injector and offset wells in adjacent compartment except one producer which showed a strong response across the fault. By correlating the MRT results with seismic profile and well completion it became possible to establish how exactly the main pay is communicating between the compartments. It also carried few learning points on how to interpret results of cross-well tracers and MRT in terms of reservoir properties.

Unveiling the “invisible” druggable conformations of GDP-bound inactive Ras

The prevalent view on whether Ras is druggable has gradually changed in the recent decade with the discovery of effective inhibitors binding to cryptic sites unseen in the native structures. Despite the promising advances, therapeutics development toward higher potency and specificity is challenged by the elusive nature of these binding pockets. Here we derive a conformational ensemble of guanosine diphosphate (GDP)-bound inactive Ras by integrating spin relaxation-validated atomistic simulation with NMR chemical shifts and residual dipolar couplings, which provides a quantitative delineation of the intrinsic dynamics up to the microsecond timescale. The experimentally informed ensemble unequivocally demonstrates the preformation of both surface-exposed and buried cryptic sites in Ras•GDP, advocating design of inhibition by targeting the transient druggable conformers that are invisible to conventional experimental methods. The viability of the ensemble-based rational design has been established by retrospective testing of the ability of the Ras•GDP ensemble to identify known ligands from decoys in virtual screening.

Could machine learning aid the production of evidence reviews? A retrospective test of RobotAnalyst

Background The Observatory Evidence Service (OES) at Public Health Wales supports evidence informed decision making by conducting evidence reviews, which follow systematic review methodology, on complex public health topics. Machine-learning technologies have the potential to aid in screening studies for inclusion in reviews, and the OES have undertaken testing of one such system, RobotAnalyst, to assess its accuracy and to determine if it would increase the efficiency of the review process. Methods Retrospective testing was undertaken using three previously completed evidence reviews. For each test, references were uploaded into RobotAnalyst and the decisions made by the original reviewers were input in blocks of 25 to form a training set. The “update predictions” function generated a predicted inclusion decision for the remaining references at each test point and these were compared to the original review decisions. We calculated RobotAnalysts sensitivity, specificity, positive predictive value, false include and exclude rate and the proportion of missed references. Results Mixed levels of performance were observed. An overall increase in sensitivity as more studies were added to the training set was detected for two of the three reference sets when screened at title stage, but only in one case did RobotAnalyst produce relatively high levels of sensitivity (over 90%). This was observed in reference test set one (n = 500 references), where sensitivity increased from 51% at the start of testing to 91% after 250 references had been manually marked on the system. Although performance tended to be higher as more studies were added to the training sets, the increases were not always linear. Conclusions There may be some promise in using RobotAnalyst as a second screener, especially on larger reference sets when the human resource demands of duplicate screening are considerable. We are continuing to test RobotAnalyst both retrospectively and prospectively. Key messages Retrospective testing of RobotAnalyst observed mixed levels of performance. RobotAnalyst could potentially be utilised as a second screener for evidence review.