#Overburden stress techlog software#

When the water is drained from soil pores, it tends to cause soil settlement. Here, the term РћС– d is dry density of layer 1, D 1 is depth of first layer, РћС– sat is saturated density of layer 2, D 2 is depth of layer2, РћС– sat is saturated density of layer 3 and D 3 is depth of layer 3.Р”В®ffective stress plays vital role in soil settlement and shear strength of soil. The effective stress can be computed at the bottom of layer 3 as below Sample layer of soil is shown in the image below.

#Overburden stress techlog software#

to true vertical depth and thereafter loaded into the Techlog 2011 software for analysis. Here, the term РћС– w is unit weight of water and z w is depth of water table. vertical stresses, their contained fluids (overburden stress). The neutral pressure can be computed using the relation below. Here, the term РџС“ v is total vertical stress and u is neutral pressure. The effective stress is computed using the relation below. It increases with increasing depth of soil. This is defined as effective overburden pressure and otherwise will be called as inter-granular stress or effective stress.

The load is directly transferred through the particles contact only. When the load increases, the pore water gets drained out from the soil. Based on the results, the factors behind the instability issues in the field will be identified and recommendations will be made for future wells drilling programs.When the soil is subjected to some load, it transfers the load to water in the pores and soil grains. During the course of the study, existing field's and drilled wells available data will be analyzed and a simulation models will be utilized to simulate the stress profiles in the field. Emphasis on the role of natural fractures density will be highlighted and included in modeling inputs as well as characterizing its density across the field. The objective of this study is to investigate the wellbore instability during drilling operations as function of rock properties, in-situ earth stress and drilling parameters. Other drilling failures includes, stuck drill pipe and difficulties with logging response and log interpretation. During the field increment sever loss circulation were encountered that resulted in lost drilling times estimated in millions of US dollars with rig cost up $ 200,000/Day. The field development called for drilling vertical and deviated wells. The field under investigation is a highly geo-pressured offshore gas field. Coupling this with an intensive analysis of drilling parameters, logging, core testing and other existing wells data builds a work frame that helps in understanding the reasons behind wellbore failures and providing solutions to them. The field of rock mechanics emerged to connect those phenomena to reservoir rock properties and stress profiles. Analyzing such problems is critical for companies especially in developing offshore fields where one day lost time is in hundreds of thousands of dollars. These problematic situations are even much more complicated in fractured reservoir environments where predicting the fracture density is important. Those can vary from loss circulations up to having stuck pipes or tools that may jeopardize well integrity and potentially lead to total loss of wells and assets. A major challenge facing the oil and gas drilling operations is mitigating the encountered wellbore instability issues.