Summary In the placement process of cement slurry, treatment fluids such as spacer are pumped ahead cementitious slurry to minimize contamination by drilling fluid and ensure superior bonding casing formation. The discussed in this work can harden with time act a settable spacer. This characteristic be an advantage for well integrity if some pockets left annulus. Rheological compatibility diffe...

Drilling fluid, as an essential part of the drilling process, directly affects efficiency and safety drilling. The expansion-type oil-based leak-proof plugging fluid system is a new type with advantages such plugging, good permeability, high bearing capacity, has become hot topic in research. This paper will provide detailed introduction to composition, performance, application system.

Wellbore instability in oil and gas drilling is resulted from both mechanical and chemical factors. Hydration is produced in shale formation owing to the influence of the chemical property of drilling fluid. A new experimental method to measure diffusion coefficient of shale hydration is given, and the calculation method of experimental results is introduced. The diffusion coefficient of shale ...

Filtration index of the drilling fluid is an important parameter of well drilling, especially at drilling-in the reservoirs. Standard parameter in the study of drilling fluids is static filtration index. At the same time, it is more feasible to determine dynamic filtration index, if considering actual conditions of the well. Use of polymer carbonate-weighted drilling fluids is advisable at dril...

Piedmont tectonic belts are rich of oil and gas resources, however the intense tectonic stress and broken formation may cause great drilling problems in piedmont structures such as borehole collapse, lost circulation and gas cutting. Through analysis of in situ stress properties, bedding structure and mechanical characteristics, wellbore instability mechanism was expounded from rock mechanics, ...

Blast furnace slag (BFS) was added into drilling fluid as a mud cake modifier (MCM) for the reuse of BFS. The effects of MCM on drilling fluid rheology and shear strength of cementformation interface (SSCFI) were evaluated. The experimental results showed that the optimized formula of the drilling fluid has 1.0 wt% MCM. The simulation results showed that SSCFI increased significantly with the a...

increasing the thermal stability and resistance to bacterial attack (bioresistance) of the potato starch used in the water-based drilling fluid is the aim of this work. four types of potato starch grafted with acrylamide and a mixture of each one with acrylic acid, 2-acrylamido-2-methyl-1-propane sulfuric acid and itaconic acid were synthesized by manganese (iv)-induced redox system at the suit...

fluid properties with constant improvement in efficiency have been noticeable as important criteria in drilling operation. the main drilling fluid properties highly depend on utilization of new polymers with high efficiency in drilling fluid composition. in this paper, the performance of a new polymer, called partially hydrolyzed polyacrylamide polymer (phpa), is studied which has recently ente...

The accurate prediction of wellbore temperature distribution helps to accurately estimate well pressure profile and bottom-hole pressure (BHP) which is important in the under-balanced drilling (UBD) operation. In this paper effect of temperature variation due to heat transfer of drilling fluid with the formation and also oil and gas production from the reservoir into the annulus in under-balanc...

The increasing global energy demand has pushed the oil industry towards developing more innovative and advanced methods of enhancing oil recovery even under unfavourable technical and environmental conditions. The severity of many operational problems affecting the drilling and production of oil and gas wells is worsened by inaccessibility; hence, remedial efforts must be implemented from afar....