The purpose was to determine the reproducibility of apparent diffusion coefficient (ADC) measurements in a two-centre phase I clinical trial; and to track ADC changes in response to the sequential administration of the vascular disrupting agent, combretastatin A4 phosphate (CA4P), and the anti-angiogenic drug, bevacizumab. Sixteen patients with solid tumours received CA4P and bevacizumab treatment. Echo-planar diffusion-weighted MRI was performed using six b values (b = 0-750 s/mm(2)) before (x2), and at 3 and 72 h after a first dose of CA4P. Bevacizumab was given 4 h after a second dose of CA4P, and imaging performed 3 h post CA4P and 72 h after bevacizumab treatment. The coefficient of repeatability (r) of ADC total (all b values), ADC high (b = 100-750) and ADC low (b = 0-100) was calculated by Bland-Altman analysis. The ADC total and ADC high showed good measurement reproducibility (r% = 13.3, 14.1). There was poor reproducibility of the perfusion-sensitive ADC low (r% = 62.5). Significant increases in the median ADC total and ADC high occurred at 3 h after the second dose of CA4P (p < 0.05). ADC measurements were highly reproducible in a two-centre clinical trial setting and appear promising for evaluating the effects of drugs that target tumour vasculature.

@+vKthl 1998. SOC~[Y of Petroleum Engineers, IncThis paper was prepared for presenlalicm 81 me SP13SRM Eurock .98 held in Trondheim, Norway, &10 July 1998 'Ms paper was selected for presenmlicm by en SPE Prcgram CommiNea following retiew of Infonnawm contained in an abstract sulvnltlad by the author(s), Contents 01 the paper, as pmsanted, hava not been !Wiewed by the Society of Pelroleum Engineers and are subject 10 mmcfi.M by the author(s). The matetial, as presented, does not necessarily reffect any positim of the !3ciely of Pelmleum Engineam, its officers, or members. Papers pm.$ented at SPE meetings am subject 10 publication mvlew by Editodal Ccxnmitte.as of the Society of Petroleum Engineers. Eleclrcnic raproduclion, dlstnbutmn, of storage of any part of this paper la commercial purposes withcut Ihe written consent of the Society of Petroleum Engineers is pmhlblted. PermlsslmI to mpmduce m pflnt is restricted to an abslmct of not mom than 300 v?m% ilfustraths may not be coplacf The abstract must ccmtain conspicuous acknowledgment of where art-dby whom tlw paper was presented, Write Ubm,rian, SPE, P.0, SCM033826, Riiardson, TX 751YJ3.3K?4, U. S.A.. fax 01-972 -952 -943S, AbstractEarly efforts to driII wells in a gas field north of Bali Island, a tectonic region in Indonesia, were hampered by high costs associated with wellbore instabilities.In the recently completed late-phase development program, drilling eftlciencies and costs were improved with a strategy that included a rmk mechanics program, mud optimization, and batch &lIling. Wellbore instabilities occurred in the Ngimbang Shale, a hard, brittle, anisotropic formation, that is highly stressed. Field measurements of stresses, coupled with laboratory measurements of strength, demonstrated the presence of elevated horizontal stresses. The computed safe mud densities for weI1bore elastic stability ranged from 10 to 15 ppg, depending on location, well azimuth, hnd deviation. High mud densities did not necessarily alleviate instability, as indicated by stability-days, a method of tracking the stabletime periods of each well. Drilling-time and costs were also improved with the adoption of a synthetic mud system, a batch drilling schedule, and sound field engineering.Cost savings were substantial, and the wells are now in production.

SPE Members Abstract/Introduction Extended-Reach Drilling (ERD) is being successfully pursued by various major operators in locations world-wide. Specialized ERD equipment and operational procedures are advancing rapidly from a number of different sources. Case histories of ERD achievements and detailed analyses of specific ERD technologies are proliferating in industry literature. This paper summarizes recent advances and emerging technologies to document available systems for ERD projects and to accelerate technology transfer and development within the industry. This paper highlights recent industry ERD projects and provides specific advances in the areas of wellbore stability, drilling fluids, drilling equipment, drilling systems, and tubular design and running. Overview of Key Industry ERD Projects In spite of the publication of ERD "limits or envelopes". the limits of ERD with current technology have not yet been found. To recognize the rapid pace of "pushing back the envelope". Consider these successful ERD operations: UK Land BP Exploration has pioneered many new ERD technologies at Wytch Farm in their successful pursuit of world-record ERD achievements. BP Wytch Farm ERD involves the development of offshore oil reserves from an onshore drillsite in a scenic and environmentally sensitive Southern England location 11–31. The economic incentive was reserves development without the building of an artificial island for conventional departure wells. BP Exploration has extended achievable departures at Wytch Farm in the relatively shallow (1600m TVD) Sherwood reservoir from 4 km to nearly 7km in a period of only two years during 1993 and 1994. Well M2 was drilled to a departure of 6760m in late 1994 and Well M3 to 6818m in early 1995. Multiple world-records have been set, and reach/TVD ratios have been extended from 2.4 to 4.28. Further achievements from BP are expected. Norway Statoil and Norsk Hydro have made extraordinary progress in ERD pursuits in the Statfjord and Gullfaks fields. The Statfjord wells are drilled into reservoir at 2700m TVD. Statfjord Well C10 achieved 5km departure in 1989/1990. The first 6km departure well in the industry was achieved by Statfjord Well C3 (6.1 km) in 1991. In 1992. Well A36 achieved 5km departure in the shallower Gullfaks reservoir at 2160m TVD, resulting in a MD/TVD ratio of 2.79, among the highest at the time. In 1992/1993, Statoil's Well C2 set new world records and broke the 7km departure "barrier" for the first time in the industry. Well C2 achieved a 8.7km MD and a departure of 7.3km at the Statfjord reservoir TVD of 2700m. In 1994, Norsk Hydro's Well C26 extended these achievements further and set another new world record for well departure. Well C26 achieved 9.3km MD and a departure of 7.85km at 2770m TVD. Statoil is planning wells with measured depths of over 10km and departures on the order of 9km. Research also continues on wells with departures of 10km in the Statfjord reservoir UK Offshore Amoco UK has been among the leaders with ERD in the Arbroath and Hutton fields. Following a failed ERD attempt in 1991. Well Tl9 achieved an MD of 5.8km and a departure of 4.6km in the reservoir at 2600m in 1992. That achievement was extended with the SEER-Tl2 well which achieved an MD of 7.5km and a departure of 6.4km in 1993. Other operators in the UK sector have also drilled substantial ERD wells. Shell Expro set records at the time with the Cormorant A-l3 well with a departure of 4.7km in 1988. More recently. Shell's Tern A-5 achieved 5km departure at 2770m TVD, while their Galleon Well PN02 that achieved a 5.7km MD at a TVD of 2500m for a MD/TVD ratio of 2.3. Mobil drilled Excalibur Well ES that achieved a 6.9km MD at a TVD of 2660m, for a MD/TVD ratio of 2.60. P. 291

Managing the disposal of drilling wastes from onshore operations is an escalating concern for the petroleum industry. Many wells are drilled in agricultural areas, posing concerns to the public with respect to disposal methods for drilling wastes. It is critical to appropriately evaluate these wastes to preempt negative environmental impact from improper disposal. The careful selection of drilling fluids and treating chemicals may allow operators flexibility in selecting disposal methods. An attractive option for disposal of onshore drilling wastes is through land treatment or "landfarming". In some cases, environmental quality may be enhanced by the application of wastes that have a positive impact on plant growth. This paper presents the results of a greenhouse plant growth study designed to evaluate the potential for landfarming drilling wastes in agriculturally active areas. Drilling wastes were collected from two wells where a non-halide potassium based product was used to formulate the drilling fluid. The fluid and associated wastes (drill cuttings) were used to conduct replicated growth tests of 2 plant species in 3 geographically different soils at 5 loading concentrations. Plant growth was monitored for over 70 days with intermittent cuttings taken at specific periods. Parameters measured included growth rate, growth index, soil electrical conductivity and exchangeable and leachate potassium in the soils. At the conclusion of the growth period, samples from selected cuttings were dried, digested, and analyzed for metals uptake as compared to the control plants. In addition, non-replicated tests were conducted where germination rates were evaluated at wet waste loadings of up to 50% by volume. Static bioassays were also conducted with two different species using whole mud samples. The results of this study indicate that downhole wastes, when generated with a properly formulated drilling fluid, may be landfarmed and have no adverse effects on growth potential when applied at specific loadings. Introduction Wastes collected during drilling operations consist of the subsurface materials (cuttings) displaced to the surface by the drilling fluid and the drilling fluid adsorbed on the surface of these cuttings. These wastes may be collected and disposed of in a variety of methods, but land treatment or "landfarming" provides the most favorable combination of disposal cost, short and long term liability to the generator, and potential environmental impact. Landfarming is a process in which wastes are incorporated into a soil surface to degrade, transform or immobilize the waste constituents by biological, chemical and physical reactions. Since many wells are drilled in agriculturally active areas, the effect of landfarming on plant growth potential is extremely important. Specific concerns involve (1) the effect of soluble salts and cation mobility on germination and plant growth and (2) heavy metals uptake by the plants that could be passed along the food chain. The advent of polymer based systems and the concern for formation damage of mature domestic oilfields have led to the use of potassium based drilling fluids when penetrating sensitive producing formations. This paper presents the results of a plant growth study in which a non-halide potassium source (potassium sulfate) was used as a drilling fluid additive in an unweighted, low pH, low solids non-dispersed (LSND) mud system. Potassium sulfate was selected because it is commonly used as a fertilizer, particularly for chloride-sensitive crops. P. 163^