Abstract. The open source modeling framework MAgPIE combines economic and biophysical approaches to simulate spatially-explicit global scenarios of landuse within the 21st century and the respective interactions with the environment. Besides various other projects, it was used to simulate marker scenarios of the Shared Socio-economic Pathways (SSPs) and contributed substantially to multiple IPCC assessments. However, with growing scope and detail, the non-linear model has become increasingly complex, computational intensive, and intransparent, requiring structured approaches to improve the development and evaluation of the model. Here we provide an overview on version 4 of MAgPIE, and how it addresses these issues of increasing complexity using new technical features: modular structure, flexible detail in process dynamics, flexible spatial resolution, in-code documentation, automatized code-checking, model/output evaluation, and open accessibility. Application examples provide insights into model evaluation and region-specific analysis approaches. While this paper is focused on the general framework as such, the publication is accompanied by a detailed model documentation describing contents and equations, and by model evaluation documents giving insights into model performance for a broad range of variables. With the open source release of the MAgPIE 4 framework we hope to contribute to more transparent, reproducible and collaborative research in the field. Due to its modularity and spatial flexibility it should provide a basis for a broad range of land-related research with economic or biophysical, global or regional focus.

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The Lower Cretaceous Zubair formation in Kuwait comprises oil-bearing sands intercalated with shale sequences. Historically, drilling into this formation presented major wellbore instability issues that include hole pack-off, stuck pipe and logging tools, high over-pull, tight zones while tripping, and severe hole washouts. These well problems have a significant impact on well costs and timeline.Wells drilled in every orientation have experienced instability problems in this formation. Vertical wells have encountered major washouts and difficulties with wireline logging operations. Deviated wells have been even more unstable and often required sidetracks -greatly increasing well costs. This paper analyzes these wellbore instability problems, including the failure mechanisms, and presents the actions taken to resolve them. A solution to these instability issues is presented, which was derived by building geomechanical models using well data, drilling problem analysis, core inspection, and core -based rock mechanical test results.We used chemoporoelastic and anisotropic geomechanical models to simulate the behavior of the Zubair formation while drilling in vertical and deviated holes to understand the wellbore instability experiences.Based on the analysis, changes in mud weight, reformulation of the mud system, and modified drilling practices were incorporated in the well plan of new high-angle wells. Success was achieved in drilling the wells and running the casing in this formation with deviations as high as 80°. The study helped to achieve a large reduction in indirect NPT due to wellbore instability. This experience is also a key learning and input for designing future complex trajectories. It is expected that a major measurable impact in the form of smoother operations and optimized well cost will occur during the drilling campaign based on recommendations from this analysis.

Understanding the spatial variation of stresses and rock mechanical properties is the key to optimize strategies for field development. In geologically complex regions, as faulted and folded domains or areas of lateral facies changes, integration of the geologic structure is crucial to better predict geomechanical attributes. This has been done in an area located in the Llanos Orientales Basin (Colombia) by means of a three-dimensional geomechanical model. The model integrates knowledge of the geological structure and regional stratigraphy, data collected in more than 40 wells, and the drilling experience acquired over 20 years. The result is a high resolution 3D model, easy to handle and to update, with a number of immediate applications that go from field exploration to harvesting and abandoning. Seismically resolvable faults and horizons have been brought into three-dimensions to build a structural model of the Apiay- Suria region. The structural framework has been used to propagate the geomechanical attributes of a number of wells using geostatistical algorithms. As a result, we have built a 3D model comprising the magnitudes and orientations of the three principal stresses, the pore pressure regime, and rock mechanical properties as uniaxial rock strength, internal friction or Poisson's ratio. The resulting 3D model provides a high resolution database that maps any lateral variation of the geomechanical attributes across the field and can be used to assess wellbore stability for any future well trajectory and location. The 3D numerical geomechanical model has been also used to determine the stress conditions near the main faults. The stress tensor is here combined with a failure criterion to assess the potential for fault instability. This study provides a valuable insight on the risk of losses while drilling through these faults and the possibility of seal rupture and leakage during injection and hydraulic fracturing activities.

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