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Abstract THE ROLE OF PETROLEUM OILS IN THE EFFECTIVEAND SAFE APPLICATION OF PESTICIDES Rsum Major advances in the effective and safe application of pesticides in crop protection have recently been achieved largely through increased knowledge of the physico-chemical factors necessary to improve the qualitative and quantitative deposition of the chemical on plant surfaces. The paper outlines the important role of petroleum oils in imparting such properties as coverage and persistence, so essential for improving the performance of existing pesticides. Examples include the development of pesticide O/W and W/O emulsions, and the use of the latter in the bi-fluid system for aerial and ground application which promises to give clear advantages over existing methods. Petroleum oils, because of their valuable and unique properties, have already found many useful applications in the pesticides industry. For example, petroleum oils are widely used in the control of pests and diseases such as sigatoka disease on bananas', caused by a fungus, scale insects on citrus' and annual weeds in carrots'. The introduction of synthetic pesticides over the past 25 years has not decreased the need for petroleum products in pest control. On the contrary, there has been a considerable increase in the use of petroleum products mainly as blending components for a variety of purposes. The paper will show how the complementary biological properties of petroleum oils and selected synthetic pesticides can be combined in specially blended products. It then reviews the use of petroleum products as carriers to distribute the pesticide uniformly over the area to be treated and concludes by showing how these petroleum products can be used to formulate water-in-oil (invert) emulsions which when sprayed have special advantages over conventional oil-in-water emulsions. by J. K. EATON, Shell Research Limited,Woodstock Agricultural Research Centre, Great Britain vni-17 Des progrs importants vers l'efficacit et la scurit d'application des pesticides pour la protection des cultures ont t rcemment raliss grce en particulier une meilleure connaissance des facteurs physicochimiques ncessaires pour amliorer quantitativement et qualitativement la rtention initiale des produits chimiques sur la surface des plantes. La communication souligne le rle important des huiles de ptrole qui permettent d'obtenir bon recouvrement et persistance et sont essentielles au meilleur rendement des pesticides actuels. L'auteur prend comme exemple la mise au point d'mulsions pesticides huile dans eau et eau dans huile, et l'emploi de cette dernire dans le systme bifluide de pulvrisation arienne ou terrestre qui aura sans aucun doute de grands avantages sur les mthodes actuelles. PETROLEUM OILS AS PESTICIDES The versatile role of petroleum products in the field of pest control has already been reviewed'. It is common knowledge that emulsions of light lubricating oi
Abstract While it is certainly true that advances in technology make it possible to drill and complete many wells faster and cheaper than ever before, it is also possible to make incorrect and costly blanket assumptions that increased technology will always yield enhanced results. One such area of technology is in fluid loss control of primary well cementing. By controlling cement slurry fluid loss, casing strings can be cemented at depths, temperatures, and difficult bottom hole conditions rarely seen twenty and thirty years ago. Today, it is not uncommon for operators to routinely utilize primary cement slurries formulated to possess API fluid losses of 50 cc or less, regardless of where, or in many cases how, the well is drilled. While this kind of fluid loss control is without a doubt necessary in many areas of the world, the fact remains that cement fluid loss control additives are as a group, one of the most expensive cement additives used. The authors detail in this paper a unique, surfactant enhanced, relaxed fluid loss cement design and placement process used to successfully cement deep gas wells in the Anadarko basin of Oklahoma and Texas Panhandle. Many of the wells have final production casings or liners set in the 18,000 to 20,000 ft. range. While the authors caution that the systems and techniques presented may not be applicable to all deep wells, the general drilling history of the subject wells is examined to help detail how and why the systems work. By analyzing the information presented, it should be possible for operators to identify potential candidate wells of their own which might benefit from similar systems. An analysis of slurry/spacer design as well as placement criteria is examined in this paper. Then an economic analysis detailing where and how the cost savings are realized is reviewed. Finally, the results of the primary cement jobs are reviewed showing both enhanced bonding and hydraulic isolation, as well as significantly decreased remedial squeeze requirements. Introduction The deep Anadarko Basin of Western Oklahoma and part of the Texas Panhandle is an area known for deep, tight, gas wells. These wells can reach average depths of 12,000 ft to 18,000 ft and some may be drilled as deep as 20,000 ft. To say the area produces some very prolific wells would be a gross understatement, given post completion production rates of 13 million cubic feet of gas/day, or more for many wells. Some of the deepest, and most challenging wells drilled are in Roger Mills, Custer, Beckham, Washita, and Caddo counties of Oklahoma, and Hemphill and Wheeler counties of Texas. The most common target formations are Pennsylvanian Sands, most notably the Granite Wash, Red Fork, Morrow, and Springer. Although the characteristics vary from well to well and field to field, most of these sands can be described as having low permeability, with 0.1 md or less being common. The pore pressure gradients generally average less than 0.8 pounds per square inch, per foot of depth (psi/ft). Many Springer or Morrow wells may have slightly higher pore pressures. Although mud densities greater than 18.0 pounds per gallon at total depth on a Springer well are not unheard of; they are uncommon. The drilling mud used to drill the productive intervals can be either a low solids, water based system with densities in the 10.3 to 13.0 pound per gallon (lb/gal), or invert oil based at 14.5 to 18.0 lb/gal. The use of the invert oil based mud is due to the need for hole stability while drilling through the water sensitive Atoka Shales on some of the deeper Morrow and Springer wells. Temperature gradients in this part of the basin are low, averaging from 0.9 to 1.2 degrees Fahrenheit per 100 feet of depth. These temperature gradients will generally yield bottom hole static temperatures in the range of 190 to 270 degrees Fahrenheit. Fracture gradients generally run from a low of about 0.75 psi/ft for the Granite Wash wells to 0.95 psi/ft or more for some Springer wells. P. 349
A new, environmentally friendly polymer has been developed for use in well completion and stimulation treatments where a premium is placed on maximizing effectiveness while minimizing formation damage. This new polymer is finding uses in many operational areas such as high-permeability fracturing, gravel packing, zonal isolation pills, spacer pills, pipe line pigs, kill pills and the like. This presentation will center on its use as a low-damage, fluid loss control agent for completion operations, particularly well control during and after perforation of high-pressure, high-permeability wells.
Fluid loss Control Pills
The use of expensive, clean completion fluids is common on high-productivity, high-pressure wells to prevent the loss of productivity. High fluid loss can result in high completion cost, deep formation damage and, potentially, loss of well control; therefore, completion fluids must be effective in controlling fluid loss. A number of materials have been used for controlling fluid loss: sized particulates, viscous fluids and gelled fluids. Guar-based fluids and sized salts are commonly used due to their low cost; however, both types of systems can leave significant well damage.
Vipulanandan, Cumaraswany (University of Houston -CIGMAT) | Raheem, Aram (CIGMAT- University of Houston) | Basirat, Barhar (University of Houston - CIGMAT) | Mohammed, Ahmed (CIGMAT-University of Houston) | Richardson, Donald Alexander (RPSEA)
Drilling muds are used in oil, gas, and geothermal well drilling, and fluid loss and filter cake formation are critical issues related to successful operations. Also, the filter cake formation and fluid loss are affected by high pressure and high temperature (HPHT) in the borehole. Rate and total fluid loss from drilling mud can affect the performance of the drilling mud and well safety. Hence, it is critical to quantify not only the rate of fluid loss process but also the changes in the filter cake formation during the fluid loss process. Past studies have assumed that the permeability and solid fraction in the filter cake remained unchanged during the formation of the cake and the fluid loss was directly propositional to the square-root of time (API Model).
In the experimental part of this study, fluid loss tests were performed for 420 minutes on 2 percent and 8 percent bentonite drilling muds at 100 psig pressure and 100oC temperature. A new kinetic hyperbolic model was developed based on satisfying the basic governing conditions during fluid loss and assuming that the permeability and solid content during the filter cake formation changes with time, temperature and pressure. The new kinetic model was verified with results from various HPHT fluid loss studies reported in the literature and HPHT experiments performed during this study. The new kinetic model prediction was also compared to the API model, and it predicted both short-term (up to 30 minutes) and long-term fluid losses very well. Hence, the new kinetic model can be used to better model the filter cake formation and filter loss in real time as functions of changes in permeability and solid content in the filter cake.